The production of a given recombinant protein can vary significantly depending on the type of medium employed. The Media Optimization Kit? and Animal- Product-Free Media Optimization Kit™ determine the best media formulation for the expression of recombinant proteins in E. coli. The APF kit contains APF Certified? versions of Athena's proprietary expression media. Both kits allow the researcher to screen several specially designed formulations to identify the medium that yields the highest amount of target protein. Each dry powder kit contains enough mix to prepare 1 liter of each of the six media. The ready-to-use liquid kits contain 100mL of each media.