Table 2.

Inter- and intra-assay reproducibility of qPCR.

Gene copy numbers	Intra-assay Reproducibilitya			Interassay Reproducibilityb
	Ct (average)	SD	CV (%)	Ct (average)	SD	CV (%)
Salmonella (ssf)
8.62 × 106	26.86	0.58	2.10	26.36	0.06	0.20
8.62 × 105	30.29	0.53	1.00	29.86	0.20	0.60
8.62 × 104	33.83	0.35	1.00	33.53	0.17	0.50
8.62 × 103	36.47	0.29	0.80	36.22	0.04	0.10
8.62 × 102	39.71	0.13	0.30	39.62	0.02	0.05
8.62 × 101	42.54	0.70	1.00	42.54	0.70	1.00
Escherichia coli  (phoA)
7.92 × 105	21.67	0.97	4.00	20.83	0.02	0.10
7.92 × 104	24.99	0.80	3.00	24.29	0.001	0.01
7.92 × 103	29.00	0.89	3.00	28.23	0.03	0.10
7.92 × 102	31.65	1.08	3.00	30.72	0.21	0.70
7.92 × 101	34.39	0.47	1.00	33.97	0.001	0.02
Staphylococcus aureus  (nuc)
1.30 × 105	25.67	1.93	6.00	25.08	0.10	0.40
1.30 × 104	28.83	1.44	4.00	28.19	0.04	0.10
1.30 × 103	31.66	0.62	1.00	31.29	0.03	0.10
1.30 × 102	34.70	0.37	1.00	34.79	0.05	0.10
1.30 × 101	37.59	0.16	0.40	40.80	0.14	0.03

^aAverage between three replicates.

^bAverage between five different reactions.

Ct: cycle threshold; SD: standard deviation; CV: coefficient of variation.