Comparison of The COBAS Ampliprep/COBAS Taqman HIV-1 Test v2 (Standard assay) with an ultra-centrifugation step prior to the standard protocol (Ultrasensitive assay) in two separate dilution series (Panel 1 and 2). Input copies/ml are theoretical concentrations calculated from a dilution series originated from a plasma sample quantified by COBAS Ampliprep/COBAS Taqman HIV-1 Test, version 2. All samples were run in quadruplicate (1-4), once in each dilution step.

Table 2: Comparison of The COBAS Ampliprep/COBAS Taqman HIV-1 Test v2 (Standard assay) with an ultra-centrifugation step prior to the standard protocol (Ultrasensitive assay) in two separate dilution series (Panel 1 and 2). Input copies/ml are theoretical concentrations calculated from a dilution series originated from a plasma sample quantified by COBAS Ampliprep/COBAS Taqman HIV-1 Test, version 2. All samples were run in quadruplicate (1-4), once in each dilution step.

Panel 1	Standard assay							Ultrasensitive assay
Input copies/ml	1	2	3	4	Mean copies/ml	SD	CV	1	2	3	4	Mean copies/ml	SD	CV
2683	3284	2332	3599	3915	3283	684	21	1942	1862	1257	1639	1675	307	18 %
537	686	660	572	637	639	47	8 %	554	607	459	148	442	205	46 %
107	130	126	132	84	118	23	19	94	52	61	-	69	22	32 %
26.8	< 20	< 20	23	< 20	-	-		24	47	20	13	26	15	57 %
5.4	< 20	-	30	< 20	-	-		5.4	6.2	5.6	-	5.7	0.4	7 %
2.7	< 20	-	-	< 20	-	-		Det	Det	6.1	Det	-	-

Panel 2	Standard assay							Ultrasensitive assay
Input copies/ml	1	2	3	4	Mean copies/ml	SD	CV	1	2	3	4	Mean copies/ml	SD	CV
27	50	36	200	78	91	75	82 %	103	105	104	59	93	23 %	24 %
9	< 20	44	< 20	29	36.5	11	29%	32	27	43	24	31	8.3	27%
3	-	-	-	< 20				-	14	5.1	7	8.7	4.7	54%
1	-	-	-	-				3.2	-	2.1	2.2	2.5	0.6	24%

SD: Standard Deviation; CV: Coefficient of Variation; Det: Detected but not quantified by the ultrasensitive assay; < 20: Detected but not quantified by the standard assay (The COBAS Taqman HIV-1 test, version 2.0 from Roche).