RESUMEN
Chromosome aberration analysis has been the basis of one of core tests in genetic toxicology since guidelines were first established (DHSS (1981) Guidelines for the Testing of Chemicals for Mutagenicity. Prepared by the Committee on Mutagenicity of Chemcials in Food, Consumer Products, and the Environment, Department of Health and Social Security. Report on Health and Social Subjects, No. 24. Her Majesty's Stationery Office, London; IPCS (1985) Guide to short-term tests for detecting mutagenic and carcinogenic chemicals prepared for the IPCS by the International Commission for Protection against Environmental Mutagens and Carcinogens. Geneva, WHO). The technique consists of microscope examination of preparations of chromosomes, usually mammalian, for clastogenicity (chromosome breakage events), and agents which induce such changes are considered genotoxic.There are a number of different types of aberrations, and within types, considerable variation in their appearance. This chapter addresses aberration classification, their appearance, frequency and fate, and the range within aberration types, potential mis-classifications, and data recording and interpretation.