Table 1. LOD of the 16S rRNA gene and toxin B gene qPCR assays recovery of C. difficile spores from solution.

PCR Target	Strain	na	LOD (# cells, 95% CI)
16S rRNA gene	NAP1	3	1.0 (0.7–2.3)
	NAP4	3	1.9 (1.3–6.5)
	Overall	6	1.4 (1.1–3.4)
Toxin B gene	NAP1	3	10.4 (7.1–22.4)
	NAP4	3	52.4 (16.5–160.6)
	Overall	6	23.6 (12.5–52.2)

^an = number of independent experiments, 8 dilutions per experiment