Laser in cytometry: Applications in flow cytogenetics

Abstract

AbstractFlow cytometry has become an important tool in biomedical research and clinical diagnosis. In particular, its ability to make multiple measurements of individual particles at a rate of up to 20000 particles per second allows the quantitative characterization (“flow karyotyping”) and sorting of isolated chromosomes. Major areas of application of “flow cytogenetics” are in molecular genetics, human genetics, and tumor cytogenetics. Several approaches to increase the resolution of one and two parameter flow cytometry of chromosomes will be discussed. On one hand different algorithms of flow cytometric data processing can be applied to achieve a better signal/apparent noise ratio. To obtain a more accurate evaluation of flow karyotypes they may be approximated as a sum of Gaussian distributions. On the other hand the flow cytometric resolution of specific chromosome types can be improved by chemical modifications of the chromosomal DNA, e.g. incorporation of base analogues or in situ hybridization in suspension with specific DNA probes.