A novel in situ colony screening method to detect human immunodeficiency virus reverse transcriptase activity expressed in bacteria. Isolation of pseudorevertants of reverse transcriptase mutants.

An in situ screening procedure is described that permits the detection of RNA-dependent DNA polymerase activity in bacterial colonies expressing the reverse transcriptase of the human immunodeficiency virus. The procedure has been applied to the isolation of rare pseudorevertants of an inactive parental mutant.