Measurement of levels of aneuploidy in mammalian cells using a modified hypotonic treatment.

The use of a short hypotonic treatment can prevent scattering of chromosomes by retaining them within the cell membrane. This technique allows chromosomes to be counted accurately so that hypodiploidy can be assessed as well as hyperdiploidy. Levels of aneuploidy were measured following treatment of a low passage number Chinese hamster fibroblast cell line derived from liver (CH1-L) with colcemid, resulting in a dose-related increase in both aneuploidy and polyploidy. The system may be a valuable assay to extend the biological profile of environmental agents, particularly those that are carcinogenic but do not induce chromosome breakage.