Spore stock dilution Estimated CFU in PCR Average Ct (SD)* 10-3 dilution (108/mL level) 5 x 105 17.5 (0.4) 10-4 dilution (107/mL level) 5 x 104 21.5 (0.2) 10-5 dilution (106/mL level) 5 x 103 18.3 (0.2) 10-6 dilution (105/mL level) 5 x 102 21.5 (0.5) 10-7 dilution (104/mL level) 5 x 101 25.4 (0.3) 10-8 dilution (103/mL level) 5 28.8 (0.5) 10-9 dilution (102/mL level) 0.5 34.1 (2.3) *Averages and standard deviations are based on 3 replicates. Acronyms: CFU, colony-forming units; Ct, cycle threshold; SD, standard deviation.

Table 1: BG real-time PCR assay results for CRP BG spore dilutions added directly to the reaction.