CHARACTERIZATION OF A HUMAN-CHROMOSOME-22 ENRICHED BACTERIAL ARTIFICIAL CHROMOSOME SUBLIBRARY

Selection of chromosomal sublibraries from total human genomic librari es is critical for chromosome-based physical mapping approaches. We ha ve previously reported a method of screening total human genomic libra ry using flow sorted chromosomal DNA as a hybridization probe and sele ction of a human chromosome 22-enriched sublibrary from a total human bacterial artificial chromosome (BAG) library (Nucleic Acids Res 1995; 23: 1838-39). We describe here further details of the method of const ruction as well as characterization of the chromosome 22-enriched subl ibrary thus constructed, Nearly 40% of the BAC clones that have been m apped by fluorescence in situ hybridization (FISH) analysis were local ized to chromosome 22. By screening the sublibrary using chromosome 22 -specific hybridization probes, we estimated that the sublibrary repre sents at least 2.5 x coverage of chromosome 22. This is in good agreem ent with the results from FISH mapping experiments, FISH map data also indicate that chromosome 22-specific BACs in the sublibrary represent all the subregions of chromosome 22.