Karyotyping of individual cells with flow cytometry.

As the study of metaphase chromosomes with flow cytometry presupposes mixing all chromosomes from many cells before analysis, important information is lost. To overcome this limitation we have developed a novel cell-oriented flow cytometric method for chromosome analysis. A flow cytometer supplied with a special device for disruption of metaphase chromosomes is the heart of the method. Cells with stained chromosomes are pressed into the disruption device and then converted in batches of chromosomes. Chromosome fluorescence and time intervals between fluorescence pulses are registered. There are large time intervals between neighboring batches because a sparse cell suspension is used and, in turn, there are small time intervals inside batches. Taking account of time intervals, it is possible to identify individual cell flow karyotypes. This highly productive method for individual cell analysis (100-200 cells/min) ensures detecting the changes in cell flow karyotypes, i.e., under- and overrepresentation of chromosomes, aberrations, and amplification of DNA.