TABLE 2.

Biosafety experiment: ability to detect viability of M. tuberculosis after paper-based DNA extraction

Inoculum (CFU/ml)	Amount of material inoculated into MGIT viala	MGIT culture	Time to positivity	Bacterial load/MGIT vial	Confirmation (CT)b
107	3 punchesc (replicate a)	Positive	7 days, 1 h	3 × 104	Xpert MTB (17.8)
107	3 punchesc (replicate b)	Positive	8 days, 10 h	3 × 104
107	Entire membrane (1 by 1 cm)	Positive	6 days, 1 h	1 × 105
107	Washings from SLCd	Positive	8 days, 10 h
107	20-μl culture + plain membrane	Positive	4 days, 10 h	2 × 105
107	20-μl culture (positive control)	Positive	5 days	2 × 105
106	3 punchesc (replicate a)	Positive	9 days, 13 h	3 × 103	Xpert MTB (22.3)
106	3 punchesc (replicate b)	Positive	12 days, 7 h	3 × 103
106	Entire membrane (1 by 1 cm)	Positive	7 days, 17 h	1 × 104	Xpert MTB (18.2)
106	Washings from SLC	Positive	9 days, 9 h
106	20-μl culture + plain membrane	Positive	7 days	2 × 104
105	3 punchesc (replicate a)	Positive	25 days, 1 h	3 × 102
105	3 punchesc (replicate b)	Positive	25 days, 13 h	3 × 102
105	Entire membrane (1 cm by 1 cm)	Positive	10 days, 11 h	1 × 103	Xpert MTB (20.1)
105	20 μl Culture (positive control)	Positive	7 days, 17 h	2 × 103
	Negative control (replicate a)	Negative	No growth at the end of 42 days
	Negative control (replicate b)	Negative

^aExperiments conducted in duplicate are labeled as replicate a and b.

^bC_T, Xpert cycle threshold defined as the number of cycles required for the fluorescent signal to cross the threshold (i.e., exceed background level).

^cThree punches were cut from the center of the Genedrive sample loading cassette and inoculated into the MGIT vial.

^dSLC, sample loading cassette.