TABLE 1.
Summary of nonmolecular quantitative CMV assays
| Assay | Turnaround time | Sample processing (blood) | Reporting of results | Batch testing | Reproducibility (reference) | Equipment and facilities needed | Advantages | Disadvantages |
|---|---|---|---|---|---|---|---|---|
| Conventional cell culture | 2–4 wk | Recovery of PMN within a few hours | No. of PFU or TCID50 | NAa | Low (38) | Cell culture facility, light microscopy | Virus isolate available for susceptibility testing | Low sensitivity; very slow CPEc; risk of bacterial or fungal contamination; large set of dilutions needed; rapid loss of viability in clinical specimens |
| Shell vial assay | 16–48 h | Recovery of PMN within a few hours | No. of infectious foci (p72 antigen) | NA | Unknown | Cell culture facility, IFb or light microscopy | Can be used with nonblood samples; detection of infectious virus; rapidity of procedure | Low sensitivity; risk of cell toxicity with blood samples; not well suited for large numbers of samples; rapid loss of viability in clinical specimens |
| pp65 antigenemia assay | 5 h | Recovery of PMN within 4–6 h | No. of positive cells (pp65 antigen per 1.5 × 105 or 2 × 105 cells) | Variable (e.g., 20 to 30 samples) | Few data, relatively low (177) | Cytospin (facultative); IF or light microscopy | Rapidity of procedure | Requires rapid sample processing for reliable quantitation; not well suited for large numbers of samples |
a
NA, not applicable.
b
IF, immunofluorescent.
c
CPE, cytopathic effect.