Table 3.
Dependence of Sensitivity on Specimen Type and Input Volume
| Specimen input volume (μl) | Lower limit of detection (IU/mL) at 95% hit-rate
|
||
|---|---|---|---|
| Dilution in K3-EDTA plasma | Dilution in citrate plasma | Dilution in serum | |
| 50 | 544 | ND | |
| 100 | 367 | ND | ND |
| 200 | 234 | 172 | 112 |
| 500 | 494 | ND | ND |
| 850 | >1000 | 87 | 110 |
ND, not determined.
The WHO Parvovirus DNA international standard was diluted in K3-EDTA plasma, citrate plasma, and serum to cover a range of 1000-10 IU/mL. Fifty to 850 microliters of the samples as taken from the options of the TNAI Kit were extrated using the TNAI Kit on the COBAS AmpliPrep instrument and the corresponding eluates analysed with the LightCycler Parvovirus B19 Quantification Kit. The lower limit of detection was calculated employing the PROBIT algorithm as described.14