One thousand colony forming units (CFU) of C. difficile VA17, VA11, and ATCC 43598 spores were exposed to 1 mL of germinants in a test tube for 1, 3, 5, 10, or 30 minutes under ambient conditions (22°C, aerobic). At the appropriate time point, spores were washed 3 times to remove germinants and then resuspended in 1 mL of pH 1.5 hydrochloric acid for 10 minutes. Spore suspensions were neutralized with phosphate-buffered saline and washed to remove hydrochloric acid. Contents were spread on a plate to enumerate the recovery of viable spores. The means of data from triplicate experiments are presented. Error bars indicate standard error.