Fluorescence in situ hybridization of metaphase chromosomes in suspension

Abstract

Purpose : To describe a new method for FISH analysis of metaphase chromosomes in suspension. Materials and methods : Metaphase chromosomes in suspension were isolated from a Chinese hamster human hybrid cell line, 314-2 (1) Y, and a human cell line, GM 130B. During suspension hybridization, specific chromosomes were labeled from these two cell lines using either biotin-labeled human genomic DNA, a directly labeled human pancentromere DNA probe or a chromosome #1 locus-specific probe. Results : The method allows, for the first time, recovery of large numbers of isolated individual hybridized chromosomes with good morphology for both human ×hamster hybrid and human cell lines. The results showed that 46-73% of the starting number of total chromosomes can be recovered after a FISH in suspension procedure. The well-preserved morphology of hybridized metaphase chromosomes allowed (1) rapid detection of individual human and hamster chromosome aberrations, (2) rapid counting of the painted human chromosomes and (3) fast, clear detection of chromosome region-specific probes. This method offers a new tool to assay chromosomes and DNA: it offers the possibility to develop new techniques for sorting chromosomes based on FISH signals, for early detection and screening of genetic diseases and for bulk measurement of both balanced or unbalanced chromosomal exchanges and rearrangements. Conclusion : The potential of the method described should facilitate fast, sensitive population monitoring, and increase sensitivity of the measurements in chromosome-based biodosimetry.