The purpose of the in vitro chromosome aberration test is to identify agents that
cause structural chromosome aberrations in cultured mammalian somatic cells. Structural
aberrations may be of two types: chromosome or chromatid.The in vitro chromosome aberration
test may employ cultures of established cell lines, cell strains or primary cell cultures.
Cell cultures are exposed to the test substance (liquid or solid) both with and without
metabolic activation during about 1.5 normal cell cycle lengths. At least three analysable
concentrations of the test substance should be used. At each concentration duplicate
cultures should normally be used. At predetermined intervals after exposure of cell
cultures to the test substance, the cells are treated with a metaphase-arresting substance,
harvested, stained. Metaphase cells are analysed microscopically for the presence
of chromosome aberrations.