Immunoprecipitation/Western blot analysis of the p53 protein from F9 cells after UV irradiation. F9 cells were irradiated with UV light (20 J/m2) and harvested at 0, 0.5, 1, 3, and 7 hr postradiation (lanes 1–5 left to right). The p53 protein was immunoprecipitated by mAb Pab246, and the precipitate was analyzed on an SDS/polyacrylamide gel. The bands were transferred and Western blots were carried out with either Pab421 (421) or alpha-392 antibody. The position of p53 is indicated and the molecular weight markers are shown. The exposure for the ECL reagent was 10 sec for 421 and α-392.