TABLE 3.
Rates of inhibition of BD GeneOhm MRSA PCR following different methods of swab extraction
| Sample preparationa | No. of samples | No. (%) of samples showing:
|
|
|---|---|---|---|
| PCR inhibition | PCR inhibition after freeze-thawb | ||
| Saline | 370 | 18 (4.9) | 0 (0) |
| 200 μl ACP | 142 | 61 (43.0) | ND |
| 300 μl ACP | 327 | 52 (15.9) | 3 (0.9) |
a
The extracts for PCR were prepared by vortexing the swab in saline and adding an aliquot to 200 μl ACP, adding 200 μl ACP directly to the swab, or adding 300 μl ACP directly to the swab. ACP, achromopeptidase.
b
Samples initially inhibited were frozen at −80°C for at least 24 h, and PCR was then repeated.