MONOVARIATE ANALYSIS OF HUMAN FIBROBLAST CHROMOSOMES BY FLOW CYTOFLUOROMETRY

Chromosome suspensions were isolated from cultured human fibroblasts, stained with different fluorochromes: propidium iodide, chromomycin A( 3), bis-benzimide (H33258), or 4,6-diamino-2-phenylindole (DAPI), and analyzed in a laser flow fluorimeter. The resulting histograms were ex amined to identify individual chromosome peaks and to reveal chromosom es that can be isolated with high purity. Peaks of chromosomes 13, 17, and 20 are well resolved, so that these chromosomes can be sorted as highly pure fractions. Chromosomes 5, 6, 8, 14, and 15 display peaks p artly overlapping with neighboring ones, and upon monovariate analysis can thus be isolated only with limited purity (2%). Chromosomes 1/2, 3/4, 7/X, 9/12, 16/18, and 19/21/22 cannot be discriminated for succes sful sorting. The results obtained offer a choice of chromosomes promi sing for high-purity sorting and subsequent DNA cloning.