Cytogenetic analysis of human chromosomes and its value for the estimation of genetic risk.

A short review of present-day contradictory opinions on the usefulness of human chromosomal analysis in the system of chemical mutagen testing is illustrated by examples of the results achieved by both conventional and banding techniques. The results include exposures of human chromosomes to ECHH and TEPA in vitro, and to ECHH, vinyl chloride and Imuran in vivo. Exposures of human lymphocytes in vitro to the chemical to be tested for mutagenicity are recommended as one of the tests to be included in the system of mutagenicity testing, parallel with all other tests on mammalian and submammalian levels. The testing of human chromosomes of people exposed to chemicals in vivo is considered essential.