Randomly picked cosmid clones overlap thepyrB andoriC gap in the physical map of theE.colichromosome

Abstract
Sets of overlapping cosmid clones generated by random sampling and fingerprinting methods complement data at pyr B(96.5′) and ori C (84′) in the published physical map of E.coli [7]. A new cloning strategy using sheared DNA, and a low copy, inducible cosmid vector were used in order to reduce bias in libraries, in conjunction with micro-methods for preparing cosmid DNA from a large number of clones. Our results are relevant to the design of the best approach to the physical mapping of large genomes.