[Rapid restriction mapping of DNA cloned in cosmid or lambda phage vectors].

A procedure for rapid restriction mapping of cosmid or lambda phage clones has been developed. The mapping of cosmid is based on linearization of circular cosmid DNA in vitro by the phage lambda terminase. Partial digestion products are selectively labelled at the right or left cos cohesive termini by hybridization with [32P] oligonucleotides complementary to the single-strand cos end. After gel electrophoresis and autoradiography, the restriction map can be directly determined from the "ladder" of partial digestion products of cosmid or lambda clones with computer program or by hand.