ANALYSIS AND GENOTYPING OF PCR PRODUCTS OF THE AMPLICOR HIV-1 KIT

The Roche Amplicor PCR kit was used to detect HIV-1 DNA in UK patients of known serostatus. Four false-negative and/or equivocal results wer e obtained from patients who were known to be anti HIV seropositive (T osswill et al., 1994). Cells from the blood of these patients were sho wn to contain HIV DNA after extraction, concentration and amplificatio n by nested PCR using primers flanking those in the kit. To determine whether DNA sequence divergence was the cause of these discrepancies, the gag region targeted by the primers in the kit was sequenced for sp ecimens giving positive, equivocal and false-negative results. No grea ter degree of sequence divergence was found within the primer and prob e target regions among the equivocals and false-negatives than among t he positive control specimens. The few misleading results were probabl y attributable to low copy numbers of proviral DNA in these specimens. Sequences obtained from the target and flanking regions of the kit we re sufficient to allow the genotype of the virus to be determined.