In situ immunoassays for gene translation products in phage plaques and bacterial colonies.

A series of simple, in situ immunoassays have been developed which can be used in screening for translation products of genes cloned in vitro recombination experiments with either phage or plasmid vectors. Antigen-antibody complex formation occurring within a vector-phage plaque can be used to detect the production of a specific protein from an amplified gene. Immunoassays of colonies lysed in situ either by lambda prophage induction or by biochemical means afford a much higher level of sensitivity than the plaque assay probably adequate to detect the production of a few molecules of protein per cell.