Rapid method for identifying subclones bridging gaps between contiguous DNA sequences.

Randomly sequencing of a limited number of unidirectional deletion subclones efficiently generated contiguous DNA sequences with some gaps between them. Gap-bridging subclones were identified by agarose gel electrophoresis. Those located at either end of each individual contiguous sequence were used as standard marker molecules; the subclones between them proved to be correctly identified in most cases. A 4064 bp DNA fragment containing the psr gene was sequenced with the strategy described in this paper.