The HIV-1 amplicon was detected by a 5′fluorescein (FAM) conjugated probe, and the internal control amplicon (HPR, see below) was detected by a 5′ conjugated Quasar 670 probe (Biosearch Technologies; Petaluma, CA.) Sequences of the forward and reverse primers, hybridization probes, and quenching oligonucleotide were described previously (Tang et al., 2007). (