UV photolesion repair. Wild-type (C5RO), TTD-A (TTD1BR, TTD99RO, and TTD14PV), and XPA (XP12RO) primary fibroblasts were grown in a 14.5-cm dish. The cells were washed with PBS and UV irradiated at 5 J/m2. DNA was isolated at different time points (0, 1, 2, 4, 8, 16, and 24 h) after UV irradiation. (a) Amount of 6-4PP measured by ELISA, using a 6-4PP-specific antibody. The amount of 6-4PP measured directly after UV irradiation was set at 100%. (b) Amount of CPD measured by ELISA, using a CPD-specific antibody. The amount of CPD measured directly after UV was set at 100%.