Figure 2

Acquired thermotolerance assays for Ssa1-4. Overnight culture was diluted in fresh YPD medium to an OD_600nm = 0.1 and then the cells were grown to exponential phase to a density of 3 × 10⁶ cells/ml. Cells were then re-suspended in fresh medium to a density of 5 × 10⁶ cells/ml. An aliquot (T_-1) was then shifted to ice. The cultures were then incubated at 39°C for 1 hour to induce Hsp104 expression to protect against heat shock. Cells were then incubated at 47°C for 0, 10, 20, 30 and 40 minutes (T₀-T₄) and plated on YPD and 3 mM Gdn-HCl for comparative growth analysis. Representative spots shown in the figure are a neat concentration from a 1 in 5 serial dilution series. The plates were then incubated at 30°C for 3 days and were monitored for cellular thermotolerance. Cells without pre-treatment show virtually no growth at T₁ (data not shown).