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The substitution of traditionally produced meat, one of the largest contributors to climate change, for cell-cultured meat would greatly favor the conservation of wildlife and environmental integrity. Cell-cultured meat is expensive, growth factors in the cell culture media contributing with over 95% of the total production cost. 

ORF genetics offers recombinant growth factors produced by transgenic barley plantswhich is a perfect host to reduce protein production cost and provide endotoxin-free products. Efficient target protein extraction and purification are crucial steps in the protein processing and finding conditions to achieve higher growth factor yields are the main drivers of optimization experiments.In this study, extraction of two growth factors, human PDGF-BB (Platelet-derived growth factor BB) and bovine FGF basic (Fibroblast growth factor basic) were optimized and in case of the human PDGF-BB, a DoE (design of experiment) based experimental screening was performed to improve magnetic bead-based affinity purification. Before the magnetic separation, a preliminary affinity resin screening was performed with IMAC columns chelated with different metals to reveal which metal binds the 6xHis-tag containing human PDGF-BB protein with the highest affinity and to use the corresponding magnetic bead in the screening experiments.

Through a series of extraction experiments 50 mM Kpi, 500 mM NaCl, 10% glycerol, 5 mM MgCl2, pH 7.5 was found to be the optimal buffer for human PDGF-BB extraction and 50 mM Kpi, 500 mM NaCl, 10 mM BeMeOH, pH 7.5 optimal for bovine FGFb extraction. Affinity resin screening of human PDGF-BB with IMAC columns proved nickel to be the metal which binds human PDGF-BB with a 6xHis-tag with the highest affinity. Design of Experiment (DoE) software, JMP, was used to optimize Nickel- NTA type magnetic bead separation of human PDGF-BB by identifying the significant factors in the process. The screening design and the statistical analysis determining the imidazole concentration during washing, the bead:seed ratio and binding time to be the most significant factors contributing to the human PDGF-BB yield.

These optimization designs and experimental setups can be built upon for further growth factor purification optimization, and contributing to cost effective production of growth factors and helping cell-cultured meat to the global food market.