Evidence of DNA repair in organ cultures of hamster tracheal epithelium following exposure to gas phase singlet oxygen.

Autoradiographic identification of unscheduled DNA synthesis (UDS) in short-term organ culture of hamster tracheal epithelium has been used as a predictive test for mutagenic and/or carcinogenic compounds. Tracheal explants were treated for 2 h with singlet delta oxygen plus [3H]thymidine. Silver grains over the nuclei of epithelial cells from the superficial layer of the mucosa were observed, indicating UDS. Control cultures, exposed to the gas phase without singlet oxygen, failed to elicit UDS.