High-resolution analysis of human peripheral lymphocyte chromosomes by flow cytometry

A method for high-resolution analysis of the human karyotype by flow cytometry has been developed. Metaphase chromosomes are prepared from short-term peripheral blood cultures, stained with ethidium bromide, and analyzed on a standard fluorescence-activated cell sorter (FACS-II). Flow karyotypes with up to 20 peaks can be obtained with coefficients of variation in the range 1-2%. At this level of resolution the contribution of many of the human chromosomes can be evaluated separately. Significant and reproducible differences between normal individuals have been detected and have been correlated with differences in the centric heterochromatin of certain chromosomes as revealed in their C-banded karyotypes.