. 2001 Oct;67(10):4685–4693. doi: 10.1128/AEM.67.10.4685-4693.2001

TABLE 4.

Effectiveness of DNase in elimination of nonviable Vibrio cells prior to DNA extraction

Strain	Treatment	No. of CFU g⁻¹		DNA concn (ng μl⁻¹)^a	ΔRQ value^b
Strain	Treatment	Initial	Final	DNA concn (ng μl⁻¹)^a	ΔRQ value^b
V. cholerae O1 (ATCC 14035)	None	7.2 × 10⁷	6.5 × 10⁷	108	35.2
V. cholerae O1 (ATCC 14035)				111	35.4
				105	35.8
	DNase	7.2 × 10⁷	6.2 × 10⁶	90	37.5
				92	37.8
				89	37.0
V. cholerae O139 (ATCC 51394)	None	6.4 × 10⁷	5.8 × 10⁷	100	35.2
V. cholerae O139 (ATCC 51394)				104	35.5
				96	35.4
	DNase	6.4 × 10⁷	5.3 × 10⁶	89	37.0
				91	37.2
				87	37.4

DNA was amplified with the hlyA TaqMan primers in the presence of the hlyA fluorogenic probe. The values shown are from three separate experiments. The DNA samples were analyzed in triplicate for each PCR.

Positive values were assigned when the ΔRQ was greater than the ΔRQ threshold value, based on the average value of the no-template controls (n = 4). ΔRQ values are the arithmetic mean of the triplicate DNA samples in each PCR analysis.