TABLE 5.

Accuracy of real-time PCR assay for L. pneumophila in dilutions of L. pneumophila cultures and water samples

Sample	Theoretical no. of cells	CFU
Dilutionsa	290,009.33	260,000
	20,571.56	80,000
	890.19	460
	144.63	170
	7.41	12
	7,149.40	5,700
	1,126.81	730
	91.65	125
	19,065.39	20,100
	2,070.24	2,100
	223.10	170
	15.35	70
	37,224.95	21,200
	1,253.37	1,200
	33.34	150
	4,634.98	3,800
	1,404.79	340
	71.86	25
	1.35	5
	21,046.20	22,300
	3,169.13	1,340
	216.41	120
	20.65	12
	2,233.79	2,500
	442.27	290
	18,802.82	2,670
	1,549.30	220
	2,183.10	310
	232.39	33
	35.21	5
Water samplesb	17,029	1,800
	13,555	120
	54,088	1,200
	2,057	70
	826	12
	6,735	200
	453	20
	16	2
	13,555	120
	826	12
	2,057	70
	62	6
	274	2
	4,268	28
	21,230	280
	4,268	28
	274	2
	7,267	230
	62	6
	9,775	1,600
	1,364	1,600
	1,061	160
	227	160
	146	12
	43	2
	1,761	40
	106	4
	9,731	70
	67	16
	11,568,079	236,000
	60,898	8,148
	1,256	580
	3,620,056	24,638
	31,442	10,670
	3,819	1,261

^aC_t values determined from the analysis of different dilutions of L. pneumophila cultures were extrapolated to the external standard regression curve to calculate the theoretical number of cells per reaction.

^bC_t values determined from the analysis of different water samples were extrapolated to the external standard regression curve to calculate the theoretical number of cells per reaction.