Cytosine arabinoside, vinblastine, 5-fluorouracil and 2-aminoanthracene testing in the in vitro micronucleus assay with L5178Y mouse lymphoma cells at Sanofi Aventis, with different cytotoxicity measurements, in support of the draft OECD Test Guideline on In Vitro Mammalian Cell Micronucleus Test.

Cytosine arabinoside (a nucleoside analogue that inhibits the gap-filling step of excision repair), vinblastine (an aneugen that inhibits tubulin polymerisation), 5-fluorouracil (a nucleoside analogue with a steep response profile), and 2-aminoanthracene (a metabolism-dependent reference genotoxin) were tested in the in vitro micronucleus assay with L5178Y mouse lymphoma cells, without cytokinesis block. The four chemicals were independently evaluated in two Sanofi Aventis laboratories, one of which used an image analyser to score micronuclei, while the other scored micronucleated cells manually. Very similar results were obtained in the two laboratories, highlighting the robustness of the assay.