Fig. 2. (A) Strains were spotted in 5-fold serial dilutions onto plates without (left and middle) or with 0.005% MMS (right) and grown at 30°C (left and right) or 37°C (middle) for 3 days. (B) Exponentially growing cells were exposed to 0.05% MMS for the times indicated and then plated onto YPD. Percentage cell survival was plotted against time in MMS. (C) Plasmid repair assay was performed by transforming either supercoiled or XbaI-linearized pRS413 into various yeast strains (described in Figure 1A). The number of HIS⁺ colonies obtained with linear versus supercoiled DNA was taken as a measure of NHEJ efficiency.