TABLE 3.
Precision of ultrasensitive HIV-1 MONITOR Testa
| Specimen and no. of input RNA copies/mlb | Mean calculated RNA concn (no. of copies/ml) | RNA concn (no. of copies/ml)
|
Within-run variation
|
Between-day variation
|
Between-operator variation
|
Total
|
|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Minimum | Maximum | SD (no. of RNA copies/ml) | CV (%) | SD (no. of RNA copies/ml) | CV (%) | SD (no. of RNA copies/ml) | CV (%) | SD (no. of RNA copies/ml) | CV (%) | ||
| VQA | |||||||||||
| 250 | 375 | 165 | 1,287 | 111 | 29.5 | 57 | 15.2 | 38 | 10.1 | 130 | 34.7 |
| 25,000 | 27,844 | 13,695 | 90,526 | 8,348 | 30.0 | 5,023 | 18.0 | 0c | 0c | 9,742 | 35.0 |
| Clinical | |||||||||||
| 500 | 710 | 355 | 1,202 | 132 | 18.7 | 90 | 12.7 | 0c | 0c | 160 | 22.5 |
| 25,000 | 29,444 | 17,380 | 55,540 | 6,111 | 20.8 | 1,988 | 6.8 | 0c | 0c | 6,426 | 21.8 |
These calculations were performed as described in the EP5T guideline of the National Committee for Clinical Laboratory Standards (19) for within-run, between-day, and between-operator variations and total precision. Between-day variation includes variation between runs; between-run variation within 1 day could not be calculated because each operator performed only one run per day. The total number of replicates for each specimen is 100.
VQA are dilutions of the viral stock from ACTG. Clinical specimens were obtained from HIV-positive patients.
The estimate of variance was negative and was set to zero in accordance with the guideline of the National Committee for Clinical Laboratory Standards (19).