TABLE 2.

Estimation of HHV-6 DNA copy number in spiked serum samples by various PCR assays

No. of spiked HHV-6A genome copies	Resulta by the following assay (assay type):
	1 (real-time PCR)	2 (real-time PCR)	3 (nested PCR)	4 (real-time PCR)	5 (LAMP)	6 (real-time PCR)	7 (PCR-EIA)	8 (real-time PCR)	9 (real-time PCR)
100,000	122,071	16,707	+	39,090	+	56,406	+	245,250	172,000
10,000	10,326	1,736	+	4,575	+	8,631	+	10,690	21,800
1,000	425b	223	+	8	+	903	+	1,265	2,500
100	111	28	+	13	−	113	+	51	300
100	31	19	+	0	+	30	+	0	200
10	+c	1	−	46	−	27	+	0	16
10	16	7	+	0	+	29	+	0	11
1	0	19	−	0	+	0	+	0	0
1	0	0	+	0	−	0	+	0	0
0	0	0	−	0	−	0	−	0	0
0	0	0	−	0	−	0	−	0	0

^aResults are presented quantitatively (in numbers of copies) or qualitatively (a positive [+] or a negative [−] result).

^bThis sample contained PCR inhibitors.

^cOne of three PCR replicates gave a positive amplification.