[Two-parameter flow fluorescence analysis of human chromosomes. Quantitative processing]

A procedure for the quantitative analysis of the results of fluorimetric studies on human chromosomes in a flow is described. The procedure enables one to simultaneously follow two parameters by using two fluorochromes, one of which is selective to the GC-, and the other, to AT base pairs of DNA. Thus, it becomes possible to derive from the experimentally obtained distributions an information on the relative DNA content in individual chromosomes, differences in DNA content between homologous chromosomes, the relative number of chromosomes of each type in the sample tested, as well as on the percent ratio of AT and GC base pairs in a particular chromosome. In addition, the procedure enables one to assign, with a high degree of accuracy, the peaks on experimental distributions to the objects of analysis chromosomes. The analysis cutting off the extreme combines the method of components with the least square method, as applied to the peaks of the Gaussian shape. The first step involves the filtration of the starting experimental data from contaminating signals from both the parts of degraded chromosomes and stained cytoplasm fragments, and from chromosome aggregates. The procedure is realized as a package of programs for IBM-compatible PC/AT computers (486 and later versions), which permits one to perform a comprehensive analysis of two-parameter distributions of chromosome fluorescence signals to solve a number of problems, such as the identification of chromosome aberrations in cell lines tested, quantitative comparison of distinguishing features of homologous chromosomes and whole chromosome sets.