HIV-1 resistance genotyping on dried serum spots.

Objective: To assess the feasibility of HIV-1 group M resistance genotyping on dried serum spots, by testing samples from previously untreated patients, patients on treatment, and patients having stopped treatment, representing a wide genetic diversity panel.

Methods: Serum samples from 62 HIV-1-infected Caucasian and African patients, with viral load values from 715 copies/ml to more than 750,000 copies/ml, were deposited on filter paper. After elution and RNA extraction, nested RT-PCR was used to amplify the protease and RT regions of the pol gene.