TABLE 2.

Noroviruses amplified by real-time RT-PCR of stool extracts and accompanying T_ms of the amplicons, slopes of the standard curves, correlation coefficients (R²) of the standard curves, and the presence of inhibitors in 1 μl of undiluted extract

Genogroup	Clustera	Representative virus	Tm (°C)	Slope	R2	Inhibitorsb
I	1	Norwalk	81.84	−0.344	0.999	No
	2	Southampton	83.00	−0.447	0.997	No
	3	Desert Shield	82.39	−0.357	0.984	Yes
	4	Chiba	83.79	−0.803	0.974	No
	5	Musgrove	83.17	−0.388	0.981	No
II	1	Hawaii	83.82	−0.390	0.970	Yes
	2	Snow Mountain	82.67	−0.428	0.991	No
	3	Toronto	81.18	−0.459	1.000	No
	4	Lordsdale	83.96	−0.400	0.968	Yes
	5	Hillingdon	83.34	−0.364	0.998	Yes
	6	Seacroft	84.90	−0.669	1.000	Yes
	7	Leeds	84.90	−0.590	1.000	Yes
	8	Amsterdam	82.81	−0.337	0.995	No

^aGenetic clusters are based on criteria described by Ando et al. (1).

^bA “yes” indicates that the real-time RT-PCR reaction was partially inhibited by the use of 1 μl of stool extract in the real-time RT-PCR reaction mix.