Human chromosome-specific DNA libraries: use of an oligodeoxynucleotide probe to detect non-recombinants.

The frequencies of non-recombinants are directly determined in 21 human DNA libraries prepared from flow-purified chromosomes. A radiolabeled 18-base oligodeoxynucleotide, whose sequence spans the cloning site, stably hybridizes to non-recombinants. When the cloning site is interrupted by an insert, less stable hybridization occurs. Non-recombinant frequencies range from 1-34% with the frequency of false positives being less than 1%. Libraries are being prepared for each human chromosome as part of the National Laboratory Gene Library Project and the specifications of seven new libraries are presented.