DNA from mouse embryo cells that had been treated in culture with 7-methylbenz[a]anthracene-3H was degraded with enzymes to deoxyribonucleosides, and deoxyribonucleoside-hydrocarbon products were separated from the normal deoxyribonucleosides by chromatography on Sephadex LH-20 columns eluted with water: methanol gradients. The 7-methylbenz[a]anthracene-3H-deoxyribonucleoside products were eluted as two peaks, the second of which appears to consist of at least two products. Only one product peak was released by treatment of the DNA with dilute acid. The material in both peaks that was released by enzyme digestion exhibited the thin-layer chromatographic behavior anticipated for hydrocarbon-deoxyribonucleoside products. Similar column elution profiles were obtained with enzyme digests of DNA isolated from mouse skin, mouse embryo cells in primary culture, and human embryo lung cells in primary culture following treatment with 7-methylbenz[a]anthracene-3H.

In addition to the tritium present in the hydrocarbondeoxyribonucleoside products, a substantial portion of the tritium associated with the DNA from the above sources was found in the normal deoxyribonucleosides. The chromatographic system described separates the normal deoxyribonucleosides from the hydrocarbon-deoxyribonucleoside products and allows the actual amount of hydrocarbon bound to DNA to be determined.


This work was supported in part by grants to the Chester Beatty Research Institute from the Medical Research Council and the Cancer Research Campaign.

This content is only available via PDF.