TABLE 2.

Performance of the hly-IAC Q-PCR with various media commonly used for Listeria

Medium	Value obtained with:
	hly system (FAM)			IAC system (VIC)
	CTa	ΔRnb	Relative accuracyc	CTd	ΔRnb
Double-distilled water	30.15 ± 0.15	0.95 ± 0.02	94.76	33.55 ± 0.61	0.55 ± 0.26
BPW	30.05 ± 0.16	0.98 ± 0.03	100.50	33.95 ± 0.52	0.60 ± 0.19
BHI	30.22 ± 0.12	0.96 ± 0.02	90.94	33.79 ± 0.49	0.65 ± 0.22
Half-Fraser	36.55 ± 1.05	0.70 ± 0.05	2.20	38.20 ± 1.20	0.13 ± 0.04
Fraser	37.25 ± 1.20	0.72 ± 0.05	1.45	38.52 ± 1.05	0.11 ± 0.04

^aCycle number at which fluorescence intensity equals a fixed threshold. FAM C_T values (mean plus or minus standard deviation) were calculated with a prefixed threshold at 0.035 and a baseline from cycles 3 to 15.

^bΔR_n is the difference between R⁺n (reporter emission intensity/passive reference emission intensity) and R⁻n (background reporter emission intensity/passive reference emission intensity [calculated in number of template controls]) (3).

^cDegree of correspondence between the response obtained by the reference method (2) and the response obtained by the alternative (Q-PCR) method.

^dVIC C_T values were calculated with a prefixed threshold at 0.035 and a baseline from cycles 3 to 23.