Table 3.
Covariates investigated by linear regression methods in this study
| Covariate | Explanation |
|---|---|
| Sample vol | Vol of sample used for DNA extraction |
| DNA extraction system | Extraction platform used to extract DNA from sample—Roche, Qiagen, or combined other systemsa |
| Elution vol | Vol used to elute DNA at the end of extraction |
| PCR amplification system | Amplification platform used to perform real-time PCR—Roche, Applied Biosystems, or combined other systemsb |
| Template vol | Vol of DNA eluate used in each PCR |
| PCR vol | Final vol of each PCR |
| PCR target | Internal transcribed spacer target, 18S rRNA target, 28S rRNA target, or mitochondrial DNA target for Aspergillus PCR |
| Internal control | Internal control PCR used (yes/no) |
a
bioMérieux EasyMag and Promega Wizard and Maxwell systems. Note one Qiagen system and one method using the bioMérieux EasyMag were excluded due to systemic contamination. The Cepheid GeneExpert was excluded on the basis of not being designed for use with serum.
b
Cepheid SmartCycler and Corbett Rotorgene 6000. Note one method using the Stratagene Mx3000p and one using the Roche Lightcycler 2.0 were excluded due to systemic contamination. The Cepheid GeneExpert was excluded on the basis of not being designed for use with serum.