The effect of different DNA isolation methods on the outcome of high-risk HPV testing.

High-risk human papillomavirus (hr-HPV) testing is widely used, but different DNA isolation methods may give variable results in PCR determinations. To evaluate the effect of different DNA isolation methods on the HPV results, DNA was isolated from 180 consecutive cervical samples with the manual Amplilute kit, or the standard automated or a modified MagNAPure LC (MPLC) protocol. The DNA was then tested for hr-HPV with the AMPLICOR HPV-test, and the HPV-genotype was determined with the Linear Array (LA) test. The concordance of the three DNA isolation methods is 90-93% and 88-92% between the HPV-tests from DNA isolated by any of the three isolation methods and LA. The sensitivity, specificity, percentage of false negatives and false positives compared to the LA detected hrHPV subtypes are similar for the manual and standard MPLC, but the specificity of the modified MPLC was much lower and the percentage of false positives much higher. In conclusion both the manual and standard MPLC DNA isolation methods give good HPV results. The standard MPLC is the fastest DNA isolation method.