In the context of protein expression, the DHFR selection system is employed to ensure that cells produce a high level of a recombinant protein. By linking the expression of the desired protein to the expression of DHFR, researchers can use selective pressure (e.g., methotrexate, an inhibitor of DHFR) to isolate and amplify cells that express both DHFR and the target protein. This dual selection mechanism enhances the efficiency and yield of protein production.
