Table 3.
Estimated Extra-Poisson Variation and Effect of Cryopreservation After Adjustment for Systematic Assay Scale Differences Between 3 Assay Groups, at the Aliquot, Batch, and Assay Levels
| Level of Analysis | Estimated Extra-Poisson Variation, Posterior Median (95% CI), Fold Change | |||
|---|---|---|---|---|
| 3 Assay Groups (n = 9 Assays) | Classic QVOAs (n = 3) | Classic QVOAs (RNA/ Digital p24) (n = 2) | Next-Generation QVOAs (n = 4) | |
| Aliquot level | 2.2 (1.9–2.6) | 1.6 (1.0–2.4) | 1.0 (1.0–1.8) | 2.5 (2.1–3.5) |
| Batch level (alone) | 1.2 (1.0–1.8) | 1.4 (1.0–2.5) | 2.7 (1.8–4.9) | 1.0 (1.0–1.9) |
| Aliquot + batch | 2.3 (2.0–2.7) | 1.9 (1.4–3.0) | 2.7 (1.9–5.0) | 2.6 (2.1–3.6) |
| Assay level (alone) | 2.1 (1.6–2.9) | 1.5 (1.0–2.8) | 1.7 (1.0–9.8) | 2.1 (1.0–4.0) |
| Aliquot + batch + assay | 3.1 (2.6–3.9) | 2.2 (1.5–3.9) | 3.4 (2.1–12.9) | 3.4 (2.6–5.4) |
| Assay type | 1.1 (1.0–2.2) | NA | NA | NA |
| Aliquot + batch + assay + assay type | 3.2 (2.6–4.3) | NA | NA | NA |
| Frozen effect, % | −22 (−47 to 13) | −37 (−77 to 51) | −22 (−77 to 175) | −18 (−52 to 39) |
Abbreviations: CI, credible interval; NA, not applicable; QVOAs, quantitative viral outgrowth assays. Classic QVOA: QVOA employing standard sensitivity p24 Ag ELISA; Classic QVOAs (RNA/Digital p24): QVOA employing ultrasensitive RNA or digital readout; Next-Generation QVOA: inducible viral outgrowth assay.