Proteins create cellular matrices, catalyze biochemical reactions, and form signaling pathways to respond to external stimuli. Studies of protein structure and function increase researchers’ understanding about the foundations of life. However, because most proteins are difficult to obtain commercially, it is important to establish sources that can provide researchers with plentiful supplies of proteins. In recombinant protein expression, a gene encoding a protein of interest is cloned into an expression vector (usually a plasmid) and transferred into a host cell…