[Chromosome Fractionation in a Saccharose Density Gradient for Subsequent Flow Sorting]

The human chromosomes were obtained from lymphoblastoid cell line BOLD with normal karyotype, and separated on the basis of their size by velocity sedimentation at 190 g in sucrose gradient. Different chromosomal fractions were stained by applying fluorochromes with different DNA-base specificity: Hoechst 33258 and Olivomycine and were analysed using dual laser cell-sorter ATC-3000 (Brucker). Velocity sedimentation allowed to enrich certain fractions by individual chromosomes and thus speed up the sorting rate from 90 up to 200 chromosomes per second.