Fig. 4. FACS analysis of mgs1-18 rad18Δ cells. (A) FACS analysis of the DNA content of asynchronized cells. Cells were incubated to early log phase and then shifted to 37°C for 6 h. (B) FACS analysis of the DNA content of synchronized cells. Cells were synchronized at G₁ by treatment with α-factor at 26°C and then released at 37°C. Aliquots were taken at the indicated time points. DNA content was measured by FACS.