A recombination based method to rapidly assess specificity of two-hybrid clones in yeast.

The yeast two-hybrid system is frequently used to identify protein-protein interactions. Confirming the specificity of candidate clones requires separation and isolation of yeast plasmids, propagation in bacteria and testing combinations of DNA-binding and activation domain hybrids in yeast. In order to simplify this procedure, we developed a rapid method based on PCR amplification of library insert DNAs and in vivo cloning into the activation domain hybrid vector. Reporter gene activity is assayed in parallel for combinations with different DNA-binding domain hybrids. Further characterization of inserts does not require plasmid isolation and intermediate hosts.