Cadmium (Cd), a toxic heavy metal and probable carcinogen in humans, appears to have potential anti-cancer activity in pre-clinical systems. This observation led us to develop a method for measuring cellular Cd and DNA-bound Cd following micromolar exposures to cadmium dichloride. Cultured human ovarian cancer cell lines were used. Following low level exposures to cadmium dichloride (CdCl2), atomic absorption spectrometry with Zeeman background correction was used to measure total cell associated Cd in wet-ashed cells, and the lower limits of detection was at 100 pg of Cd per 106 cells. In cellular DNA isolated by cesium chloride density gradient centrifugation, levels of 1.5 Cd lesions (Cd molecules) per 106 nucleotides were reproducibly detected. Standard curves with samples yielded 76.4 6.7% recovery when using picogram quantities of Cd. Manipulation of the total amount of biological material used, can further improve detection limits. Thus, this method is suitable for the detection of Cd in biological matrixes after low levels of Cd exposure, and shows good performance in terms of the level of sensitivity and reproducibility.

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