Cell-free protein expression offers a rapid, reliable technique for synthesis of proteins. Successfully synthesizing large quantities of high-quality product requires finding the optimal protein expression conditions, such as the type of cellular extract used. Lysate choice for the cell- free reaction can affect expression feasibility, yield and cost. Which extract gives the best results? Here, we compare two of the most common: E. coli and wheat germ.
Cell-free systems are mainly used for in-vitro protein synthesis and can be considered as a powerful tool in genetic code reprogramming, involving the amber codon. In this use, the non-proteinogenic amino-acids are incorporated into proteins by charging them to suppressor-tRNAs molecules that reprogram the existing codons. However, cell-free systems are also used to engineer genetic circuits with applications for in-vitro biology or metabolic engineering.