Table 1 System suitability criteria (criteria 1–3) and test sample criteria (criteria 4–9) for the PRNT
Criterion | Description |
|---|---|
1 | The negative control wells should have no plaques |
2 | No more than one well on the control plate should have a monolayer disturbed by nonspecific means, e.g., mechanical damage greater than five plaques or cells sloughing off |
3 | The mean plaque count of the VOC should give a plaque count ranging from 60 to 110 mean pfu/well |
4 | None of the test sample wells should have a monolayer disturbed by nonspecific means, e.g., mechanical damage greater than five plaques or cells sloughing off |
5 | Plaques should not be too numerous to count in any well |
6 | In wells with <5 pfu, the duplicate counts for that test sample dilution should be <10 |
7 | In wells with ≥5 pfu, the duplicate counts for each test sample dilution should not be more than twofold different from each other |
8 | If the mean pfu/well at any dilution is <80% of VOC, the mean pfu/well at greatest dilution should be greater than mean pfu/well at least dilution of test sample |
9 | Mean pfu/well should not be between 50–80% of mean VOC at any dilution of test sample (i.e., response curve does not cross 50% neutralization) |
