In vivo SCE analysis using bromodeoxyuridine, iododeoxyuridine, and chlorodeoxyuridine.

Sister-chromatid exchange (SCE) frequencies were determined for mouse and rabbit bone-marrow cells following incorporation of 3 different halogenated analogues of thymidine. For both species the SCE frequency was highest for chlorodeoxyuridine, lowest for iododeoxyuridine and intermediate for bromodeoxyuridine. The study demonstrates that halogenated pyrimidine analogues other than brominated compounds can be used for in vivo SCE analysis and that their effects on baseline SCE frequencies are qualitatively similar to results of previous in vitro studies.