PREPARATIVE IN-SITU HYBRIDIZATION - SELECTION OF CHROMOSOME REGION-SPECIFIC LIBRARIES ON MITOTIC CHROMOSOMES

We have developed preparative in situ hybridization (Prep-ISH) of comp lex DNA populations to mitotic chromosomes as a means of generating ch romosome region-specific DNA subpopulations. Prep-ISH is a combination of two cytogenetic techniques: in situ hybridization of DNA molecules to mitotic chromosomes and chromosome microdissection. Here, we prese nt test cases demonstrating the feasibility of this approach on mouse and human genomes, using Single nuclei, single chromosomes, or single chromosomal subregions to assess sensitivity, specificity, and represe ntation of the Prep-ISH technique. Prep-ISH has a number of applicatio ns in studies of gene expression and genome organization, including ef ficient cytogenetic sorting of tissue-specific cDNAs and genomic DNA l ibraries. In addition, Prep-ISH is likely to dramatically reduce the n umber of candidate genes to aid in gene discovery efforts and to impro ve efficiency of developing transcription maps and YAC and cosmid cont igs through defined cytogenetic regions. (C) 1994 Academic Press, Inc.