The pIC plasmid and phage vectors with versatile cloning sites for recombinant selection by insertional inactivation.

The versatility of insertional inactivation of beta-galactosidase activity for subcloning and sequencing has been enhanced by combining a chemically synthesized oligonucleotide which specifies nine 6-bp-cutter restriction sites including BglII, XhoI, NruI, ClaI, SacI and EcoRV in various configurations with existing polylinkers to create a set of highly versatile cloning sites. These improved polylinkers have been inserted into plasmids (the pICs) for routine cloning of double-stranded DNA, and into chimeric phage/plasmids (the pICEMs) for biological production of single stranded DNA. The most versatile polylinker specifies 17 restriction sites in the beta-galactosidase alpha-complementing gene fragment. One of the new polylinkers was inserted into M13 DNA to produce a vector (M13mIC7) with nine cloning sites.