TABLE 2.

Decontamination by wash vs DNase vs benzonase prior to cell lysis: copy number/ng of input DNA and ratios of Mtb:host are computed from qPCR performed on same starting material that was split fourfold between the control and three test protocols ^a

Treatment	Mtb copy number/ng	Mtb treated vs control P value	Host copy number/ng	Host treated vs control P value	Mtb DNA:host DNA ratio
Control	212.3 ± 59.4	NA b	6,168 ± 1,638	NA	1:29
Wash	3,151 ± 1,369	0.0002	2,726 ± 936.4	0.0001	1:0.86
DNase	2,862 ± 733.4	0.0001	2,414 ± 1,043	0.0001	1:0.84
Benzonase	11,721 ± 7,096	0.0012	3,422 ± 2,162	0.0084	1:0.29

^a Summary of Mtb copy number and host copy number per 1 ng of input DNA as determined by qPCR and expressed as a ratio of Mtb to host copy number. Significant differences between control and treatment groups were determined by unpaired t-test with Welch’s correction (P < 0.05). Three technical qPCR replicates were done for every sample.

^b NA - Not applicable.