TABLE 2.
Sensitivities of five PCR assays for detecting C. pneumoniae DNAa
| No. of IFU detected | PCR results for assay:
|
||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | |
| 1 | ++ | ++ | ++ | ++ | ++ |
| 0.1 | ++ | ++ | ++ | ++ | ++ |
| 0.01 | +− | −+ | ++ | ++ | ++ |
| 0.005 | −+ | ++ | −+ | ++ | ++ |
| 0.001 | −− | −− | −− | −+ | +− |
| 0.0005 | −− | −− | −− | −− | −− |
a
A 1-ml aliquot of C. pneumoniae seed strain VR1310, containing 106 IFU, was extracted with a Qiagen DNA Mini-kit, and 2.5-μl aliquots of eluted DNA were tested in duplicate by five PCR assays as shown in Table 1 and described in Materials and Methods.