The effect of washing lymphocytes after in vivo treatment with streptonigrin on the yield of chromosome and chromatid aberrations in blood cultures.

Cytogenetic analyses of cultured blood lymphocytes from streptonigrin-treated female rabbits demonstrated that the yield of chemically-induced chromatid aberrations, expecially exchanges, is influenced by the method of blood handling before in vitro culture. When blood cells from treated animals were washed with tissue-culture medium before culture, chromatid breaks were observed at the same level as in the controls, and no chromatid exchanges were found. However, when duplicate aliquots of blood were inoculated directly into culture medium, without washing, elevated levels of chromatid breaks were observed and chromatid exchanges were found. These findings indicate that the clastogen, streptonigrin, was carried into the culture medium with the blood-cell inoculum.