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  • 1.
    Ahlford, Annika
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Molekylär medicin.
    Kjeldsen, Bastian
    Reimers, Jakob
    Lundmark, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Molekylär medicin.
    Romani, Massimo
    Wolff, Anders
    Syvänen, Ann-Christine
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Molekylär medicin.
    Brivio, Monica
    Dried reagents for multiplex genotyping by tag-array minisequencing to be used in microfluidic devices2010Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 135, nr 9, s. 2377-2385Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present an optimized procedure for freeze-drying and storing reagents for multiplex PCR followed by genotyping using a tag-array minisequencing assay with four color fluorescence detection which is suitable for microfluidic assay formats. A test panel was established for five cancer mutations in three codons (175, 248 and 273) of the tumor protein gene (TP53) and for 13 common single nucleotide polymorphisms (SNPs) in the TP53 gene. The activity of DNA polymerase was preserved for six months of storage after freeze-drying, and the half-life of activities of exonuclease I and shrimp alkaline phosphatase were estimated to 55 and 200 days, respectively. We conducted a systematic genotyping comparison using freeze-dried and liquid reagents. The accuracy of successful genotyping was 99.1% using freeze-dried reagents compared to liquid reagents. As a proof of concept, the genotyping protocol was carried out with freeze-dried reagents stored in reaction chambers fabricated by micromilling in a cyclic olefin copolymer substrate. The results reported in this study are a key step towards the development of an integrated microfluidic device for point-of-care DNA-based diagnostics.

  • 2.
    Artemenko, Konstantin A.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Lind, Sara Bergström
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi.
    Elfineh, Lioudmila
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Genomik.
    Mayrhofer, Corina
    Zubarev, Roman A.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Pettersson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Genomik.
    Optimization of immunoaffinity enrichment and detection: toward a comprehensive characterization of the phosphotyrosine proteome of K562 cells by liquid chromatography-mass spectrometry2011Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 136, nr 9, s. 1971-1978Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Phosphorylation of protein tyrosine residues regulates many cell functions and has also been proved to be involved in oncogenesis. Thus, the identification of the phosphotyrosine (pTyr) proteome of cells is a very important task. Since tyrosine phosphorylation represents only around 1% of the total human phosphoproteome, the study of pTyr proteins is rather challenging. Here we report the optimization study of the phosphotyrosine proteome using K562 cells as a model system. A substantial segment of the phosphotyrosine proteome of K562 cells was characterized by immunoaffinity enrichment with 4G10 and PYKD1 antibodies followed by LC-MS/MS analysis. 480 non-redundant pTyr peptides corresponding to 342 pTyr proteins were found. 141 pTyr peptides were not described elsewhere. The mass spectrometry approach involving high-resolving FTMS analysis of precursor ions and subsequent detection of CID fragments in a linear ion trap was considered as optimal. For detection of low abundant pTyr peptides pooling of individual immunoaffinity enrichments for one LC-MS/MS analysis was crucial. The enrichment properties of the monoclonal PYKD1 antibody were presented for the first time, also in comparison to the 4G10 antibody. PYKD1 was found to be more effective for protein enrichment (1.2 and 5% efficiency at peptide and protein level correspondingly), while 4G10 showed better results when peptide enrichment was performed (15% efficiency versus 3.6% at protein level). Substantially different subsets of the phosphoproteome were enriched by these antibodies. This finding together with previous studies demonstrates that comprehensive pTyr proteome characterization by immunoprecipitation requires multiple antibodies to be used for the affinity enrichment.

  • 3.
    Bailly-Chouriberry, Ludovic
    et al.
    Laboratoire des Courses Hippiques (LCH), France.
    Cormant, Florence
    Laboratoire des Courses Hippiques (LCH), France.
    Garcia, Patrice
    Laboratoire des Courses Hippiques (LCH), France.
    Lönnberg, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Szwandt, Simon
    Thermo Fisher Scientific, Hemel Hempstead, UK.
    Bondesson, Ulf
    Dept. of Chemistry, Environment and Feed Hygiene, The National Veterinary Institute (SVA), Uppsala, Sweden.
    Popot, Marie-Agnes
    Laboratoire des Courses Hippiques (LCH), France.
    Bonnaire, Yves
    Laboratoire des Courses Hippiques (LCH), France.
    A new analytical method based on anti-EPO monolith column and LC-FAIMS-MS/MS for the detection of rHuEPOs in horse plasma and urine samples2012Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 137, nr 10, s. 2445-2453Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recombinant human erythropoietin (rHuEPO) is a 30-34 kDa glycoprotein banned by the racing authorities. For some years this molecule has been detected in race horses in USA and in Europe, and even in racing camels. Although direct methods to differentiate horse endogenous EPO and rHuEPO have been developed either by LC-MS/MS or by isoelectric focusing (IEF) with double-blotting, the short confirmation time of such prohibited hormone in plasma remains a problem for horseracing doping control laboratories. In order to improve the rHuEPOs confirmation process in horse plasma or urine in terms of reliability and delay, a small anti-EPO monolith membrane contained in a disposable column (anti-EPO monolith column) has been successfully used and validated (n = 10). This new sample preparation, combined with LC-FAIMS-MS/MS, has been performed on plasma and urine samples collected from one horse which received an Eprex[registered sign] treatment during six consecutive days and a second one with a single injection of Aranesp[registered sign]. This inventive technology allowed the possibility to confirm the presence of rHuEPO within one day with a limit of detection validated for both urine and plasma at 250 pg mL-1 by means of a disposable, ready to use immunoaffinity column. The lower limit of detection (LLOD) obtained for each matrix was 100 pg mL-1. These results provide an important improvement for rHuEPO doping control in horseracing especially the possibility to confirm these banned molecules in both matrices, urine and plasma, with a confidence of two specific target peptides.

  • 4.
    Bergman, Hilde-Marlene
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Lanekoff, Ingela
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Profiling and quantifying endogenous molecules in single cells using nano-DESI MS2017Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 142, nr 19, s. 3639-3647Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Molecular profiling of single cells has the potential to significantly advance our understanding of cell function and cellular processes of importance to health and disease. In particular, small molecules with rapid turn-over rates can reveal activated metabolic pathways resulting from an altered chemical environment or cellular events such as differentiation. Consequently, techniques for quantitative metabolite detection acquired in a higher throughput manner are needed to characterize the biological variability between seemingly homogenous cells. Here, we show that nanospray desorption electrospray ionization (nano-DESI) mass spectrometry ( MS) enables sensitive molecular profiling and quantification of endogenous species in single cells in a higher throughput manner. Specifically, we show a large number of detected amino acids and phospholipids, including plasmalogens, readily detected from single cheek cells. Further, by incorporating a phosphatidylcholine ( PC) internal standard into the nano-DESI solvent, we determined the total amount of PC in one cell to be 1.2 pmoles. Finally, we describe a higher throughput approach where molecules in single cells are automatically profiled. These developments in single cell analysis provide a basis for future studies to understand cellular processes related to drug effects, cell differentiation and altered chemical microenvironments.

  • 5.
    Bergman, Hilde-Marléne
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Lundin, Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Andersson, Malin
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    Lanekoff, Ingela
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Quantitative mass spectrometry imaging of small-molecule neurotransmitters in rat brain tissue sections using nanospray desorption electrospray ionization2016Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 141, nr 12, s. 3686-3695Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Small molecule neurotransmitters are essential for the function of the nervous system, and neurotransmitter imbalances are often connected to neurological disorders. The ability to quantify such imbalances is important to provide insights into the biochemical mechanisms underlying the disorder. This proof-of-principle study presents online quantification of small molecule neurotransmitters, specifically acetylcholine, γ-aminobutyric acid (GABA) and glutamate, in rat brain tissue sections using nanospray desorption electrospray ionization (nano-DESI) mass spectrometry imaging. By incorporating deuterated internal standards in the nano-DESI solvent we show identification, accurate mapping, and quantification of these small neurotransmitters in rat brain tissue without introducing any additional sample preparation steps. We find that GABA is about twice as abundant in the medial septum-diagonal band complex (MSDB) as in the cortex, while glutamate is about twice as abundant in the cortex as compared to the MSDB. The study shows that nano-DESI is well suited for imaging of small molecule neurotransmitters in health and disease.

  • 6.
    Bergman, Nina
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Recent developments in proteomic methods and disease biomarkers2014Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 139, s. 3836-3851Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Proteomic methodologies for identification and analysis of biomarkers have gained more attention during recent years and have evolved rapidly. Identification and detection of disease biomarkers are important to foresee outbreaks of certain diseases thereby avoiding surgery and other invasive and expensive medical treatments for patients. Thus, more research into discovering new biomarkers and new methods for faster and more accurate detection is needed. It is often difficult to detect and measure biomarkers because of their low concentrations and the complexity of their respective matrices. Therefore it is hard to find and validate methods for accurate screening methods suitable for clinical use. The most recent developments during the last three years and also some historical considerations of proteomic methodologies for identification and validation of disease biomarkers are presented in this review.

  • 7.
    Bergström, Sara K.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Dahlin, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Ramström, Margareta
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Andersson, Marit
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Markides, Karin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    A simplified multidimensional approach for analysis of complex biological samples: on-line LC-CE-MS2006Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 131, nr 7, s. 791-798Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Information on protein expression, disease biomarkers or surrogate markers and genetic disorders can nowadays be achieved from analysis of complex biological samples by liquid separation coupled to mass spectrometric (MS) detection. This paper describes fast multidimensional separation by on-line liquid chromatography (LC) and capillary electrophoresis (CE), followed by electrospray ionization (ESI) Fourier transform ion cyclotron resonance (FTICR) MS detection. This detector provides ultrahigh resolution of the detected ions, mass accuracy at the ppm-level and high sensitivity. Most of the challenge of this system lies in the development of a new interface for the on-line coupling of LC to CE. The interface developed in poly(dimethylsiloxane) provides a RSD for injection repeatability of <3.5% and surface control for unspecific binding by deactivation with a cationic polymer, PolyE-323. We have evaluated the interface, as well as the overall system, with respect to robustness and deconvolution ability. Sequence coverage for bovine serum albumin (BSA) of 93% showed a high recovery of sample in the different transfer steps through the system. The detection limit for identification is 277 ng mL−1 (or 280 nM) on average for peptides. In the future, we expect LC-CE-MS to be a novel strategy for elucidating the chemistry of biological matrices.

  • 8.
    Duncan, Kyle D.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Bergman, Hilde-Marlene
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Andersson, Ingela
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    A pneumatically assisted nanospray desorption electrospray ionization source for increased solvent versatility and enhanced metabolite detection from tissue2017Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 142, nr 18, s. 3424-3431Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nanospray desorption electrospray ionization (nano-DESI) has been established as a powerful technique for mass spectrometry imaging (MSI) of biomolecules from tissue samples. The direct liquid extraction of analytes from a surface at ambient pressure negates the need for significant sample preparation or matrix application. Although many recent studies have applied nano-DESI to new and exciting applications, there has not been much work in the development and improvement of the nano-DESI source. Here, we incorporate a nebulizer to replace the self-aspirating secondary capillary in the conventional nano-DESI setup, and characterize the device by use of rat kidney tissue sections. We find that the pneumatically assisted nano-DESI device offers improved sensitivity for metabolite species by 1-3 orders of magnitude through more complete desolvation and reduced ionization suppression. Further, the pneumatically assisted nano-DESI device reduces the dependence on probe-to-surface distance and enables sampling and imaging using pure water as the nano-DESI solvent. This provides exclusive detection and imaging of many highly polar endogenous species. Overall, the developed pneumatically assisted nano-DESI device provides more versatile solvent selection and an increased sensitivity for metabolites, which generates ion images of higher contrast - allowing for more intricate studies of metabolite distribution.

  • 9.
    Duncan, Kyle D.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Fyrestam, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Lanekoff, Ingela
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Advances in mass spectrometry based single-cell metabolomics2019Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 144, nr 3, s. 782-793Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Metabolomics has grown into a prominent field contributing to the molecular understanding of complex biological processes in both health and disease. Furthermore, single-cells are known to display metabolic differences between seemingly homogeneous populations of cells. Single-cell metabolomics attempts to analyze many cellular metabolites from single cells to understand phenotypic heterogeneity, which is a significant challenge due to the low analyte abundances and limited sample volumes. Label-free metabolite detection can be achieved with mass spectrometry, which is capable of simultaneously analyzing hundreds of metabolites. Herein, we review the recent advances in mass spectrometry based single-cell metabolomics, highlighting the current state-of-the-art within the last three years, and identify the challenges to move the field forward.

  • 10.
    Dunér, Gunnar
    et al.
    Department of Chemistry, KTH.
    Anderson, Henrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik. Attana AB.
    Pei, Zhichao
    Attana AB.
    Ingemarsson, Björn
    Attana AB.
    Aastrup, Teodor
    Attana AB.
    Ramström, Olof
    Department of Chemistry, KTH.
    Signal Enhancement in Ligand-Receptor Interactions using Dynamic Polymers at Quartz Crystal Microbalance Surfaces2016Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 141, nr 13, s. 3993-3996Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The potential for signal amplification on QCM sensors by use of in situ polymerized poly(acrylic acid) brushes has been studied. A biotin derivative was immobilized on these surfaces and the interaction with anti-biotin Fabs was evaluated. Interaction data was found to be specific for the studied binding events, and the level of non-specific binding was shown to be low. The surface was proven to be suitable for regeneration, of importance for biomolecular interaction analysis and repetitive immunoassays.

    For comparison, the same interaction system was tested using commercial sensor surfaces with carboxylated self-assembled monolayers. The poly(acrylic acid) surface showed a dramatic increase in signal response with more than ten times the signal of the carboxylated self-assembled monolayer surface. Thus, the present study shows that polymers can be successfully applied to amplify responses on QCM sensors, valuable for studies of interactions between receptors and low molecular weight compounds.

  • 11.
    Duong-Thi, Minh-Dao
    et al.
    Linnaeus University, Department of Chemistry and Biomedical Sciences, SE-39182 Kalmar, Sweden.
    Bergström, Maria
    Linnaeus University, Department of Chemistry and Biomedical Sciences, SE-39182 Kalmar, Sweden.
    Edwards, Katarina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Eriksson, Jonny
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Ohlson, Sten
    Nanyang Technological University, School of Biological Sciences, Singapore 637551, Republic of Singapore.
    To Yiu Ying, Janet
    Nanyang Technological University, School of Biological Sciences, Singapore 637551, Republic of Singapore.
    Torres, Jaume
    Nanyang Technological University, School of Biological Sciences, Singapore 637551, Republic of Singapore.
    Agmo Hernández, Víctor
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Lipodisks integrated with weak affinity chromatography enable fragment screening of integral membrane proteins2016Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 141, nr 3, s. 981-988Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Membrane proteins constitute the largest class of drug targets but they present many challenges in drug discovery. Importantly, the discovery of potential drug candidates is hampered by the limited availability of efficient methods for screening drug-protein interactions. In this work we present a novel strategy for rapid identification of molecules capable of binding to a selected membrane protein. An integral membrane protein (human aquaporin-1) was incorporated into planar lipid bilayer disks (lipodisks), which were subsequently covalently coupled to porous derivatized silica and packed into HPLC columns. The obtained affinity columns were used in a typical protocol for fragment screening by weak affinity chromatography (WAC), in which one hit was identified out of a 200 compound collection. The lipodisk-based strategy, which ensures a stable and native-like lipid environment for the protein, is expected to work also with other membrane proteins and screening procedures.

  • 12.
    Eriksson, Anna
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Edwards, Katarina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Agmo Hernández, Víctor
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Cooperative adsorption behavior of phosphopeptides on TiO2 leads to biased enrichment, detection and quantification2015Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 140, nr 1, s. 303-312Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The adsorption behavior of phosphopeptides onto TiO2 surfaces was studied using the quartz crystal microbalance with dissipation monitoring (QCM-D) as the main experimental technique. The main focus is the characterization of the emergence of positive cooperativity under conditions where the peptides have a positively charged C-term. It is shown that when carrying no net charge, small water-soluble peptides as a rule develop positive cooperativity. The impact of the adsorption mechanism on the outcome of TiO2 based enrichment methods was investigated with the help of matrix assisted laser desorption-ionization mass spectrometry (MALDI-MS). The data presented illustrate how the phosphopeptide profile in the enriched material may deviate from that in the native sample, as cooperative phosphopeptides are overrepresented in the former. Furthermore, commonly employed washing and elution solutions may facilitate preferential release of certain peptides, leading to further bias in the recovered sample. Taken together, the results of the present study demonstrate that thorough understanding of the mechanisms behind the adsorption of phosphopeptides on the enrichment material is necessary in order to develop reliable qualitative and quantitative methods for phosphoproteomics.

  • 13.
    Fernandes, Daniel L. A.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
    Pavliuk, Maria V.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
    Sa, Jacinto
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
    A 3D printed microliquid jet with an adjustable nozzle diameter2015Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 140, nr 18, s. 6234-6238Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Microliquid jets have many applications, in particular in the fields of spectroscopy/analysis of samples susceptible to beam damage. Herein, we report a microliquid jet, manufactured with 3D printing technology, with a tuneable nozzle diameter output. This strategy increases the breadth of techniques that can be covered with a single microliquid jet.

  • 14.
    Haas, Julian
    et al.
    Ulm University, Germany.
    Vargas Catalán, Ernesto
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Piron, Pierre
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Karlsson, Mikael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap. Molecular Fingerprint Sweden AB, Eksätravägen 130, SE-756 55 Uppsala, Sweden .
    Mizaikoff, Boris
    Ulm University, Germany.
    Infrared Spectroscopy Based on Broadly Tunable Quantum Cascade Lasers and Polycrystalline Diamond Waveguides2018Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 143, nr 21, s. 5112-5119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recently emerging broadly tunable quantum cascade lasers (tQCL) emitting in the mid-infrared (MIR) are a versatile alternative to well established thermal emitters in combination with interferometers as applied in Fourier transform infrared (FTIR) spectroscopy. The wide and highly spectrally resolved wavelength tuning characteristics along with superior spectral energy density renders laser-based vibrational spectroscopy methods an efficient alternative vs. conventional molecular spectroscopies. Using diamond in attenuated total reflection (ATR) sensing formats benefits from the physical robustness and chemical resistivity of the internal reflective element (IRE) material. While inherent material absorption frequently limits the optical path length within diamond ATR elements, the herein presented design combining bright tQCLs with a multi-reflection polycrystalline diamond (PCD) ATR element enables an optical beam path length of approximately 5 cm. Thereby, sensitive spectroscopic measurements in the MIR are enabled. As an example, non-invasive glucose monitoring in human saliva is examined, highlighting the potential benefits of the proposed analytical concept with regards to exquisite sensitivity and selectivity in combination with a robust sensing interface, i.e., diamond. This approach paves the way towards directly analyzing molecular constituents in complex and potentially corrosive biomedical and biochemical matrices.

  • 15. Hartfelder, Urs
    et al.
    Szlachetko, Jakub
    Sá, Jacinto
    van Bokhoven, Jeroen A
    Determination of catalytic reaction mechanisms by isotopic frequency response.2012Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 137, nr 22, s. 5374-81Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Efficient catalysts are of extraordinary importance for the development of efficient chemical processes as well as applications such as energy storage. Rational development of catalysts requires a mechanistic understanding of the catalytic reaction. Since steady-state investigations are insufficient to gain mechanistic understanding, transient methods such as SSITKA and frequency response have been developed. In this paper we provide a theoretical basis for a frequency response method based on variations in the isotopic composition of the reactant. This approach is particularly useful, since it permits transient investigations under quasi-steady state conditions and because the response is linear.

  • 16.
    Herr, Amy E.
    et al.
    Univ Calif Berkeley, Berkeley, CA 94720 USA.
    Kitamori, Takehiko
    Univ Tokyo, Tokyo, Japan.
    Landegren, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Molekylära verktyg.
    Kamali-Moghaddam, Masood
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Molekylära verktyg.
    Next wave advances in single-cell analyses2019Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 144, nr 3, s. 735-737Artikel i tidskrift (Övrigt vetenskapligt)
  • 17. Kelly, Orla
    et al.
    Duffy, Martin J
    King, Raymond B
    Belshaw, Louise
    Williams, Ian D
    Sá, Jacinto
    Calvert, Chris R
    Greenwood, Jason B
    Femtosecond lasers for mass spectrometry: proposed application to catalytic hydrogenation of butadiene.2012Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 137, nr 1, s. 64-9Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mass spectra from the interaction of intense, femtosecond laser pulses with 1,3-butadiene, 1-butene, and n-butane have been obtained. The proportion of the fragment ions produced as a function of intensity, pulse length, and wavelength was investigated. Potential mass spectrometry applications, for example in the analysis of catalytic reaction products, are discussed.

  • 18.
    Kjeldsen, Frank
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap, MMS, medicinsk masspektrometri.
    Savitski, Mikhail M.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap, MMS, medicinsk masspektrometri.
    Nielsen, Michael L.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap, MMS, medicinsk masspektrometri.
    Shi, L.
    Zubarev, Roman A.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap, MMS, medicinsk masspektrometri.
    On studying protein phosphorylation patterns using bottom-up LC-MS/MS: the case of human alpha-casein2007Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 132, nr 8, s. 768-776Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Most proteomics studies involving mapping post-translational modifications, such as the phosphorylation of serine and threonine, are performed today using the 'bottom-up' approach. This approach involves enzymatic cleavage of proteins, most often by trypsin, with subsequent nano-LC-MS/MS. The occupancy rates of phosphosites in proteins may differ by orders of magnitude, and thus the occupancy rate must be reported for each occupied phosphosite. To highlight potential pitfalls in quantifying the occupancy rates, αs1- casein from human milk was selected as a model molecule representing moderately phosphorylated proteins. For this purpose, human milk from one Caucasian woman in the eighth month of lactation was used. The phosphorylation level of caseins is believed to have major implications for the formation of micelles that are involved in delivering valuable calcium phosphate and other minerals to the new-born. Human αs1-casein has been reported to be much less phosphorylated than ruminant caseins, which may indicate a different function of caseins in humans. Revealing the phosphorylation pattern in human casein can thus shed light on its function. The current study found that the sequence region between the residues Ser70 and Ser76 in human αs1-casein is in fact phosphorylated, contrary to previous knowledge. The site of the most abundant phosphorylation is Ser75, in agreement with the known action of the mammary gland casein kinase. There is evidence for the second phosphorylation in that region, possibly at Ser73. Earlier reported positions of phosphorylations at Ser18 and Ser26 are also confirmed, but not the dominance of Ser18 phosphorylation. The occupancy rates at Ser18, Ser26 and Ser75 are estimated to be (7 ± 2), (20 ± 6) and (27 ± 9)%, respectively. Owing to differences in the ionization efficiency between phosphorylated and unphosphorylated peptides a 30% error margin is added to the occupancy rates. The highlighted pitfalls of the bottom-up strategy include the sensitivity of enzymes to proximal acidic and phosphorylated residues and the presence of multiple isoforms, including unexpected ones, of the tryptic peptides. The utility of the earlier introduced PhosTS_hunter and ModifiComb approaches for evading the latter pitfall is demonstrated.

  • 19.
    Källsten, Malin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi. Recipharm OT Chem AB, Uppsala, Sweden.
    Hartmann, Rafael
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Preparativ läkemedelskemi.
    Artemenko, Konstantin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Bergström Lind, Sara
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Lehmann, Fredrik
    Recipharm OT Chem AB, Uppsala, Sweden.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Qualitative analysis of antibody-drug conjugates (ADCs): an experimental comparison of analytical techniques of cysteine-linked ADCs.2018Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 143, nr 22, s. 5487-5496Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Antibody-drug conjugates (ADCs) are an emerging type of biotherapeutics that utilize multiple tissue-specific antibodies combined with a range of linker designs to enable the transportation and selective release of cytotoxic drugs in close proximity to tumours. Consisting of antibodies conjugated to small drug molecules through a variety of linkers, ADCs are chemically complex analytes. Here we present a unique experimental comparison of four techniques for ADC analysis: hydrophobic interaction chromatography (HIC-UV/Vis), reversed phase liquid chromatography mass spectrometry (RPLC-MS), using either a QToF or an Orbitrap analyser, and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Four different ADCs consisting of Trastuzumab, monomethyl auristatin E (MMAE) and a peptidic linker moiety differing in their respective stoichiometric ratios in regard to drug-to-antibody ratio (DAR) were used for the comparison. We found that the determined DAR from all techniques was comparable, while the accuracy of the molecular weights for the conjugated light and heavy chain differed more extensively. This indicates that the choice of a mass analyser is more crucial for determining the accurate weights of the light and heavy chains than to evaluate the DAR of a given batch. However, ambiguous DAR assignment in HIC-UV/Vis or bias for either the light or heavy chain fragments in the mass spectrometry-based techniques can influence the obtained average DAR value and the use of complementary techniques is advisable. Out of the four techniques evaluated, HIC-UV/Vis and MALDI required less time to obtain an average DAR value and would therefore be good for initial screenings in the early stages of the discovery phase of new ADCs.

  • 20. Lanekoff, Ingela
    et al.
    Geydebrekht, Oleg
    Pinchuk, Grigoriy E
    Konopka, Allan E
    Laskin, Julia
    Spatially resolved analysis of glycolipids and metabolites in living Synechococcus sp. PCC 7002 using nanospray desorption electrospray ionization2013Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 138, nr 7, s. 1971-1978Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Microorganisms release a diversity of organic compounds that couple interspecies metabolism, enable communication, or provide benefits to other microbes. Increased knowledge of microbial metabolite production will contribute to understanding of the dynamic microbial world and can potentially lead to new developments in drug discovery, biofuel production, and clinical research. Nanospray desorption electrospray ionization (nano-DESI) is an ambient ionization technique that enables detailed chemical characterization of molecules from a specific location on a surface without special sample pretreatment. Due to its ambient nature, living bacterial colonies growing on agar plates can be rapidly analyzed without affecting the viability of the colony. In this study we demonstrate for the first time the utility of nano-DESI for spatial profiling of chemical gradients generated by microbial communities on agar plates. We found that despite the high salt content of the agar used in this study (~350 mM), nano-DESI analysis enables detailed characterization of metabolites produced by the Synechococcus sp. PCC 7002 colonies. High resolution mass spectrometry and MS/MS analysis of the living Synechococcus sp. PCC 7002 colonies allowed us to detect metabolites and lipids on the colony and on the surrounding agar, and confirm their identities. High sensitivity of nano-DESI enabled identification of several glycolipids that have not been previously reported by extracting the cells using conventional methods. Spatial profiling demonstrated that a majority of lipids and metabolites were localized on the colony while sucrose and glucosylglycerol, an osmoprotective compound produced by cyanobacteria, were secreted onto agar. Furthermore, we demonstrated that the chemical gradients of sucrose and glucosylglycerol on agar depend on the age of the colony. The methodology presented in this study will facilitate future studies focused on molecular-level characterization of interactions between bacterial colonies.

  • 21. Lanekoff, Ingela
    et al.
    Stevens, Susan L
    Stenzel-Poore, Mary P
    Laskin, Julia
    Matrix effects in biological mass spectrometry imaging: identification and compensation2014Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 139, nr 14, s. 3528-3532Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Matrix effects in mass spectrometry imaging (MSI) may affect the observed molecular distribution in chemical and biological systems. In this study, we use mouse brain tissue of a middle cerebral artery occlusion (MCAO) stroke model to examine matrix effects in nanospray desorption electrospray ionization MSI (nano-DESI MSI). This is achieved by normalizing the intensity of the sodium and potassium adducts of endogenous phosphatidylcholine (PC) species to the intensity of the corresponding adduct of the PC standard supplied at a constant rate with the nano-DESI solvent. The use of MCAO model with an ischemic region localized to one hemisphere of the brain enables immediate comparison of matrix effects within one ion image. Furthermore, significant differences in sodium and potassium concentrations in the ischemic region in comparison with the healthy tissue allowed us to distinguish between two types of matrix effects. Specifically, we discuss matrix effects originating from variations in alkali metal concentrations and matrix effects originating from variations in the molecular composition of the tissue. Compensation for both types of matrix effects was achieved by normalizing the signals corresponding to endogenous PC to the signals of the standards. This approach, which does not introduce any complexity in sample preparation, efficiently compensates for signal variations resulting from differences in the local concentrations of sodium and potassium in tissue sections and from the complexity of the extracted analyte mixture derived from local variations in molecular composition.

  • 22.
    Minero, Antonio S. Gabriel
    et al.
    Technical University of Denmark.
    Nogueira, Catarina
    BluSense Diagnostics, Copenhagen, Denmark.
    Rizzi, Giovanni
    Technical University of Denmark.
    Tian, Bo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets fysik.
    Fock, Jeppe
    Technical University of Denmark.
    Donolato, Marco
    BluSense Diagnostics, Copenhagen, Denmark.
    Strömberg, Mattias
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets fysik.
    Fougt Hansen, Mikkel
    Technical University of Denmark.
    Sequence-specific validation of LAMP amplicons in real-time optomagnetic detection of Dengue serotype 2 synthetic DNA2017Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 142, nr 18, s. 3441-3450Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on an optomagnetic technique optimised for real-time molecular detection of Dengue fever virus under ideal as well as non-ideal laboratory conditions using two different detection approaches. The first approach is based on the detection of the hydrodynamic volume of streptavidin coated magnetic nanoparticles attached to biotinylated LAMP amplicons. We demonstrate detection of sub-femtomolar Dengue DNA target concentrations in the ideal contamination-free lab environment within 20 min. The second detection approach is based on sequence-specific binding of functionalised magnetic nanoparticles to loops of LAMP amplicons. Melting studies reveal that true positive and spurious amplicons have different melting points and this allows us to discriminate between them. This is found to be in a good agreement with subsequent studies on real-time sequence-specific discrimination of LAMP amplicons. The specific binding causes clustering of magnetic nanoparticles via binding to multiple sites (loops) emerging in the elongation phase of LAMP. Formation of nanoclusters is monitored via the depletion of the optomagnetic signal due to free nanoparticles. After sequence-specific validation, we claim detection of down to 100 fM of Dengue target after 20 min of LAMP with a contamination background.

  • 23.
    Pettersson Dahlin, Andreas
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Wetterhall, Magnus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Liljegren, Gustav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Bergström, Sara K.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Andrén, Per
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    Nyholm, Leif
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Materialkemi GU.
    Markides, Karin E
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Capillary electrophoresis coupled to mass spectrometry from a polymer modified poly(dimethylsiloxane) microchip with an integrated graphite electrospray tip2005Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 130, nr 2, s. 193-199Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hybrid capillary-poly(dimethysiloxane) (PDMS) microchips with integrated electrospray ionization (ESI) tips were directly fabricated by casting PDMS in a mould. The shapes of the emitter tips were drilled into the mould, which produced highly reproducible three-dimensional tips. Due to the fabrication method of the microfluidic devices, no sealing was necessary and it was possible to produce a perfect channel modified by PolyE-323, an aliphatic polyamine coating agent. A variety of different coating procedures were also evaluated for the outside of the emitter tip. Dusting graphite on a thin unpolymerised PDMS layer followed by polymerisation was proven to be the most suitable procedure. The emitter tips showed excellent electrochemical properties and durabilities. The coating of the emitter was eventually passivated, but not lost, and could be regenerated by electrochemical means. The excellent electrochemical stability was further confirmed in long term electrospray experiments, in which the emitter sprayed continuously for more than 180 h. The PolyE-323 was found suitable for systems that integrate rigid fused silica and soft PDMS technology, since it simply could be applied successfully to both materials. The spray stability was confirmed from the recording of a total ion chromatogram in which the electrospray current exhibited a relative standard deviation of 3.9% for a 30 min run. CE-ESI-MS separations of peptides were carried out within 2 min using the hybrid PDMS chip resulting in similar efficiencies as for fused silica capillaries of the same length and thus with no measurable band broadening effects, originating from the PDMS emitter.

  • 24.
    Sa, Jacinto
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi. Polish Acad Sci, Inst Phys Chem, Warsaw, Poland..
    Czapla-Masztafiak, Joanna
    Polish Acad Sci, Inst Nucl Sci, PL-31342 Krakow, Poland.;Paul Scherrer Inst, CH-5232 Villigen, Switzerland..
    Lipiec, Ewelina
    Polish Acad Sci, Inst Nucl Sci, PL-31342 Krakow, Poland..
    Kayser, Yves
    Paul Scherrer Inst, CH-5232 Villigen, Switzerland..
    Fernandes, Daniel L. A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
    Szlachetko, Jakub
    Paul Scherrer Inst, CH-5232 Villigen, Switzerland.;Jan Kochanowski Univ Humanities & Sci, Inst Phys, PL-25406 Kielce, Poland..
    Dufrasne, Francois
    Univ Libre Bruxelles, Lab Chim Pharmaceut Organ, Campus Pl CP205-5,Bd Triomphe, B-1050 Brussels, Belgium..
    Berger, Gilles
    Univ Libre Bruxelles, Lab Chim Pharmaceut Organ, Campus Pl CP205-5,Bd Triomphe, B-1050 Brussels, Belgium.;MIT, Dept Chem, Cambridge, MA 02139 USA..
    Resonant X-ray emission spectroscopy of platinum(II) anticancer complexes2016Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 141, nr 4, s. 1226-1232Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Platinum-based drugs are commonly used in cancer treatment. The biological activity of a metallodrug is obviously closely related to its chemical and stereochemical characteristics. An overlooked aspect is the effect of the ligand to the electronic structure of the metal atom (coordinated atom). We report herein a Resonant X-ray Emission Spectroscopy (RXES) study on the chemical speciation of chiral platinum complexes in which diastereomers are distinguished on the basis of their metal electronic configuration. This demonstrates RXES high chemical speciation capabilities, a necessary property to further investigate the reactivity of the Pt atom towards nucleophiles or bionucleophiles, and an important complement the previously reported RXES abilities, namely that it can be employed for in situ studies at physiological concentrations.

  • 25. Sa, Jacinto
    et al.
    Friedli, Peter
    Geiger, Richard
    Lerch, Philippe
    Rittmann-Frank, Mercedes H.
    Milne, Christopher J.
    Szlachetko, Jakub
    Santomauro, Fabio G.
    van Bokhoven, Jeroen A.
    Chergui, Majed
    Rossi, Michel J.
    Sigg, Hans
    Transient mid-IR study of electron dynamics in TiO2 conduction band (vol 138, pg 1966, 2013)2013Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 138, nr 24, s. 7420-7420Artikel i tidskrift (Refereegranskat)
  • 26. Shibata, Aya
    et al.
    Nakano, Yukiko
    Ito, Mika
    Araki, Mika
    Zhang, Jie
    Yoshida, Yasuhiko
    Shuto, Satoshi
    Mannervik, Bengt
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Biokemi.
    Mogenstern, Ralf
    Ito, Yoshihiro
    Abe, Hiroshi
    Fluorogenic probes using 4-substituted-2-nitrobenzenesulfonyl derivatives as caging groups for the analysis of human glutathione transferase catalyzed reactions2013Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 138, nr 24, s. 7326-7330Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have synthesized a series of 4-substituted-2-nitrobenzene-sulfonyl compounds for caged fluorogenic probes and conducted a Hammett plot analysis using the steady-state kinetic parameters. The results revealed that the glutathione transferase (GST) alpha catalyzed reaction was dependent on the sigma value in the same way as the non-enzymatic reaction, whereas the dependence of the sigma value of the GST mu and pi was not as pronounced as that of GST alpha.

  • 27.
    Sundström, Ingela
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    Arts, Joris
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    Westerlund, Douglas
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för analytisk farmaceutisk kemi.
    Andrén, Per E.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    In vivo investigation of brain and systemic ketobemidone metabolism2010Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 135, nr 2, s. 405-413Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ketobemidone metabolites have previously been identified in urine and plasma; here we show, for the first time, that norketobemidone and ketobemidone N-oxide are present in in vivo microdialysate from rat brain (striatum) after reverse microdialysis, suggesting striatal metabolism of ketobemidone. Ketobemidone metabolites were also identified in in vivo microdialysate samples from brain and blood, as well as in urine from rats, after subcutaneous administration of ketobemidone. Three Phase I metabolites (norketobemidone, ketobemidone N-oxide and hydroxymethoxyketobemidone) and three Phase II metabolites (glucuronic acid conjugates of ketobemidone, norketobemidone and hydroxymethoxyketobemidone) were identified in the microdialysates after subcutaneous administration. Coupled capillary liquid chromatography tandem mass spectrometry (LC-MS/MS) and SPE (boronate)-MS/MS were utilized for the analysis of the biological samples. The Phase I metabolites were identified by comparing the retention times and tandem mass spectra of the microdialysates with synthetic standards. The Phase II metabolites were identified by determination of exact masses and by comparing the tandem mass spectra of the microdialysates with those of synthetic standards for the aglycones. Hydroxyketobemidone, a catechol-type Phase I metabolite, was selectively isolated by solid-phase boronate-complexation but identified in urine alone. This work demonstrated that the in vivo microdialysis technique in combination with LC-MS/MS can be used to study the local metabolism of a drug in the brain.

  • 28. Sá, Jacinto
    et al.
    Fernandes, Daniel Luis Abreu
    Aiouache, Farid
    Goguet, Alexandre
    Hardacre, Christopher
    Lundie, David
    Naeem, Wasif
    Partridge, William P
    Stere, Cristina
    SpaciMS: spatial and temporal operando resolution of reactions within catalytic monoliths.2010Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 135, nr 9, s. 2260-72Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Monolithic catalysts are widely used as structured catalysts, especially in the abatement of pollutants. Probing what happens inside these monoliths during operation is, therefore, vital for modelling and prediction of the catalyst behavior. SpaciMS is a spatially resolved capillary-inlet mass spectroscopy system allowing for the generation of spatially resolved maps of the reactions within monoliths. In this study SpaciMS results combined with 3D CFD modelling demonstrate that SpaciMS is a highly sensitive and minimally invasive technique that can provide reaction maps as well as catalytic temporal behavior. Herein we illustrate this by examining kinetic oscillations during a CO oxidation reaction over a Pt/Rh on alumina catalyst supported on a cordierite monolith. These oscillations were only observed within the monolith by SpaciMS between 30 and 90% CO conversion. Equivalent experiments performed in a plug-flow reactor using this catalyst in a crushed form over a similar range of reaction conditions did not display any oscillations demonstrating the importance of intra monolith analysis. This work demonstrates that the SpaciMS offers an accurate and comprehensive picture of structured catalysts under operation.

  • 29. Sá, Jacinto
    et al.
    Friedli, Peter
    Geiger, Richard
    Lerch, Philippe
    Rittmann-Frank, Mercedes H
    Milne, Christopher J
    Szlachetko, Jakub
    Santomauro, Fabio G
    van Bokhoven, Jeroen A
    Chergui, Majed
    Rossi, Michel J
    Sigg, Hans
    Transient mid-IR study of electron dynamics in TiO2 conduction band.2013Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 138, nr 7, s. 1966-70Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dynamics of TiO2 conduction band electrons were followed with a novel broadband synchrotron-based transient mid-IR spectroscopy setup. The lifetime of conduction band electrons was found to be dependent on the injection method used. Direct band gap excitation results in a lifetime of 2.5 ns, whereas indirect excitation at 532 nm via Ru-N719 dye followed by injection from the dye into TiO2 results in a lifetime of 5.9 ns.

  • 30. Touitou, Jamal
    et al.
    Burch, Robbie
    Hardacre, Christopher
    McManus, Colin
    Morgan, Kevin
    Sá, Jacinto
    Goguet, Alexandre
    An in situ spatially resolved analytical technique to simultaneously probe gas phase reactions and temperature within the packed bed of a plug flow reactor.2013Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 138, nr 10, s. 2858-62Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper reports the detailed description and validation of a fully automated, computer controlled analytical method to spatially probe the gas composition and thermal characteristics in packed bed systems. As an exemplar, we have examined a heterogeneously catalysed gas phase reaction within the bed of a powdered oxide supported metal catalyst. The design of the gas sampling and the temperature recording systems are disclosed. A stationary capillary with holes drilled in its wall and a moveable reactor coupled with a mass spectrometer are used to enable sampling and analysis. This method has been designed to limit the invasiveness of the probe on the reactor by using the smallest combination of thermocouple and capillary which can be employed practically. An 80 μm (O.D.) thermocouple has been inserted in a 250 μm (O.D.) capillary. The thermocouple is aligned with the sampling holes to enable both the gas composition and temperature profiles to be simultaneously measured at equivalent spatially resolved positions. This analysis technique has been validated by studying CO oxidation over a 1% Pt/Al2O3 catalyst and the spatial resolution profiles of chemical species concentrations and temperature as a function of the axial position within the catalyst bed are reported.

  • 31.
    Ubhayasekera, Kumari
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Acharya, Santosh R.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    A novel, fast and sensitive supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS) method for analysis of arachidonic acid metabolites2018Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 143, nr 15, s. 3661-3669Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The development of a rapid, sensitive and reliable method for the quantification of bioactive arachidonic acid metabolites (AA-metabolites) in biological samples is quite challenging due to the minute concentration, short half-life and their structural complexity arising from different isomers. In this study, a simple, fast and environmentally friendly supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS) method was developed and validated for simultaneous measurement of five (PGD(2), PGE(2), PGF(2), 6KetoPGF(1) and LTB4) AA-metabolites in biological samples. These analytes were extracted by protein precipitation followed by separation and quantification. The analysis was completed within 3 minutes. The matrix matched linear calibration ranged from 0.5-100 ng mL(-1) (r(2) 0.995), whilst, the limit of quantification of PGD(2), PGE(2), PGF(2), and LTB4 was 0.5 ng mL(-1) and was 2.5 ng mL(-1) for 6KetoPGF(1). The interday and intraday precisions of the method were less than 15% while the accuracy of most of the analytes varied between 83 and 109%. Finally, as a proof of concept, the method was successfully applied for the determination of eicosanoids in human samples, which expands the possibility to explore physiological states, disease phenotypes, and novel biomarkers.

  • 32.
    Ullsten, Sara
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Söderberg, Lennart
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Ytbioteknik, Centrum för ytbioteknik.
    Folestad, Staffan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Markides, Karin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Quaternary ammonium substituted agarose as surface coating in capillary electrophoresis2004Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 129, s. 410-415Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel positively charged polymer of quaternary ammonium substituted agarose (Q-agarose) has been synthesized and explored for use as a coating in capillary electrophoresis. The fast and simple coating procedure is based on a multi-site electrostatic interaction between the polycationic agarose polymer and the negatively charged fused-silica surface. By simply flushing fused-silica capillaries with hot polymer solution a positively charged, hydrophilic deactivation layer is achieved. The polymer surface provides an intermediate electroosmotic flow of reversed direction, over a range of pH 2-11, compared to unmodified fused-silica. The coating procedure was highly reproducible with an RSD of 4%, evaluated as the electroosmotic flow mobility for 30 capillaries prepared at 10 different occasions. The application of Q-agarose coated capillaries in separation science was investigated using a set of basic drugs and model proteins and peptides. Due to the intermediate electroosmotic flow generated, the resolution of basic drugs could be increased, compared to using bare fused-silica capillaries. Moreover, the coating enabled separation of proteins and peptides with efficiencies up to 300.000 plates m(-1).

  • 33.
    Undin, Torgny
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Dahlin, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hörnaeus, Katarina
    Uppsala universitet, Science for Life Laboratory, SciLifeLab. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Bergquist, Jonas
    Uppsala universitet, Science for Life Laboratory, SciLifeLab. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Bergström Lind, Sara
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Mechanistic investigation of the on surface enzymatic digestion (oSED) protein adsorption detection method using targeted mass spectrometry2016Ingår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 141, nr 5, s. 1714-1720Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study describes our efforts to study some of the mechanistic aspects of the earlier established onsurface enzymatic digestion (oSED) method. In a multitude of application areas, it has become important to be able to fully characterize and understand selective protein adsorption to biomaterial surfaces for various applications, including biomedicine (implants), nanotechnology (microchip surfaces and sensors) and materials sciences. Herein, the investigation of the mechanistic aspects was based on microdialysis catheter tubes that were flushed with controlled protein solutions mimicking the extracellular fluid of the brain. The protein adsorption properties were monitored using high-resolution liquid chromatography tandem mass spectrometry (LC-MS/MS) with a targeted method. The temporally resolved results show that most proteins stay adsorbed onto the surface during the entire digestion process and are only cut away piece by piece, whereas smaller proteins and peptides seem to desorb rather easily from the surface. This information will simplify the interpretation of data generated using the oSED method and can also be used for the characterization of the physicochemical properties controlling the adsorption of individual proteins to specific surfaces.

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