Fig 1.

Growth of wild-type CHO-7 and mutant SRD-5 and SRD-9 cells in the presence or absence of 25HC. On day 0, cells were set up at the following densities: CHO-7 and SRD-9, 4 × 10⁴ cells per 60-mm dish; and SRD-5, 9 × 10⁴ cells per 60-mm dish. On day 1, the cells were washed once with PBS and refed every 2–3 days with medium A supplemented with 5% fetal calf lipoprotein-deficient serum in the absence or presence of 0.3 μg/ml 25HC. On day 14, the cells were washed, fixed in 95% ethanol, and stained with crystal violet.