A versatile PCR procedure which allows colony screening within a few hours

The paper describes a simple and effective protocol for screening recombinant clones, which can be used instead of usual procedures of plasmid DNA isolation and restriction. The procedure has been established by testing if transformant colonies, obtained after plating transformation mixtures, can be directly subjected to amplification of the DNA insert present in plasmid DNA. The results of PCR experiments show that amplification can be obtained starting form few bacterial cells, provided that the cells are subjected to a short lysis cycle before amplification. Amplification can be obtaine with commercially available sequencing primers, giving rise to amplification products that can be identified on the masis of their size on agarose gel electrophoresis.