A simple, three-step procedure for the large scale purification of DNA ligase from a hybrid lambda lysogen constructed in vitro.

A simple three-step procedure for the large scale purification of DNA ligase has been developed. THe source of enzyme is a strain of Escherichia coli with a hybrid lambda prophage constructed in vitro that bears the ligase overproducing gene lop 11 lig+ (Panasenko, S., Cameron, J., Davis, R. W., and Lehman, I. R. (1977) Science 196, 188-189). The procedure yields homogeneous enzyme in approximately 40% yield.