TABLE 4.

Quantification of a known amount of HIV-1 RNA subtype C in pooled CVS lavage fluids and plasma samples from HIV-negative women spiked with a known amount of HIV-1 subtype C reference control by HIV-1 RNA real-time RT-PCR using a Light Cycler apparatus^a

Expected result (log10 copies)b	Cervicovaginal secretion		Plasma
	Observed result (log10 copies)	Δlog10	Observed result (log10 copies)	Δlog10
6.00	5.90	0.10	5.73	0.27
5.00	4.95	0.05	5.02	−0.02
4.00	4.27	−0.27	3.99	0.01
3.00	3.21	−0.21	3.02	−0.02
2.70	2.92	−0.22	2.67	0.03
2.40	2.62	−0.22	2.71	−0.31
2.10	2.37	−0.28	2.05	0.04
1.80	2.13	−0.33	2.10	−0.31
Mean		−0.17		−0.04

^aΔlog₁₀ is the difference between expected log₁₀ values and observed log₁₀ values obtained with a real-time RT-PCR assay.

^bHIV-1 RNA subtype C at 10⁹ copies/ml was obtained from the Viral Diagnostic Quality Control Programme, Amsterdam, The Netherlands.