The use of an immunological probe to measure the kinetics of DNA repair in normal and UV-sensitive mammalian cell lines.

Chinese hamster ovary cells and human fibroblasts were used to study UV-light-induced repair replication and removal of antibody-binding sites. Whereas repair replication still continued 8 h post irradiation, removal of antibody-binding sites was 80% complete within 2 h and reached a plateau by 4 h. This was found to be independent of the method of DNA isolation. UV-hypersensitive CHO cells exhibited reduced levels of repair synthesis that closely correlated with the extent of removal of antibody-binding sites. XP group A, C and D cells, each of which had less than 15% of the level of repair synthesis found in the control fibroblasts, removed less than 30% of the antibody-binding sites. Group E cells demonstrated intermediate levels of DNA-repair capacity in both assays.