Protein expression and purification
Expression of proteins in E. coliExpression of a recombinant protein can be approached in general by constructing a plasmid that encodes the desired protein, introducing the plasmid into the required host cell, growing the host cells and inducing protein expression, and then lysing the cells, purifying the protein, and performing SDS-PAGE analysis to verify the presence of the protein (see figure Generation of recombinant proteins).
The protocols and recommendations given in the DNA section of this online guide for the handling and transformation of E. coli are also valid for the production of recombinant proteins. With careful choice of host strains, vectors, and growth conditions, most recombinant proteins can be cloned and expressed at high levels in E. coli. Optimal growth and expression conditions for the protein of interest should be established with small-scale cultures before large-scale protein purification is attempted.