Figure 2.

Low level BrdU incorporation does not affect cell cycle progression. (A) TK⁺ yeast cells (E1000) were grown for 2 h at 25°C in the presence of increasing amounts of BrdU (0–1600 µg/ml). After PFGE DNA was stained with SybrGold (left), transferred to nitrocellulose and the level of BrdU incorporated into chromosomes quantitated using anti-BrdU and fluorescent secondary antibodies. (B) Total incorporation is proportional to the amount of BrdU present in the medium (dark gray bars). The incorporation obtained with a concentration of 400 µg/ml BrdU in the medium affects neither the doubling time (light gray bars) nor the growth curves (C), nor cell cycle distribution (D) of the cultures. A slight increase in doubling time is seen at higher BrdU concentrations.