FIG. 2.

Spontaneous deletion frequencies (DF) in different p53 backgrounds. (A) Deletion frequencies. For each determination of deletion frequency, at least three individual transfectants of each of the three plasmid variants were pretreated with 6-TG for 2 days to reduce the background. Deletion frequencies were determined from the formula described in Materials and Methods. (B) p53 status of human lymphoblasts. Western blot analyses of p21 and p53 protein levels were performed as described previously (41).