[A novel method of chromosome distribution analysis in saccharose density gradient]

The human chromosomes distribution in a sucrose density gradient was studied using a new computer method of the quantitative analysis of flow karyotypes. The dual-parameter flow distributions of human chromosomes fluorescence intensities of the sucrose density gradient fractions were analyzed to obtain the quantity of each chromosome. The chromosomes were found to distribute over sucrose density gradient as follows: 1) fractions with low sucrose density mostly contain chromosomes 1-7, and their quantity is increased between 1.4- to 3.2-fold in comparison with the control unfractionated suspension; 2) medium density fractions are enriched with chromosomes 8-20 up to 2.4-fold; 3) fractions with a high sucrose density mostly contain small chromosomes 21-22 and fragments of broken chromosomes. So the new method of quantitative analysis of flow karyotypes allows one to determine the efficiency of enrichment and the maximally enriched fraction for any chosen chromosome. Maximally enriched fractions maximize the rate of preparative flow sorting of individual chromosomes for research or biotechnology purposes.