The NEBExpress Cell-free E. coli Protein Synthesis System is engineered to be compatible with linear DNA. However, protein yield produced from a linear DNA template is typically lower than the protein yield produced from plasmid DNA. This is because of the presence of an E. coli exonuclease, RecBCD (Exo V), which is responsible for degrading the linear DNA template. GamS can be added to the synthesis reaction to effectively inhibit the activity of RecBCD, so that the linear DNA can be stabilized for sustainable transcription.