Figure 2.

Schematic of HIV-1 QT assay. (A) Three internal calibrators, each with a unique altered 20-nucleotide internal sequence and of known RNA concentration, are added to lysis buffer with patient sample, and total nucleic acids are co-isolated. (B) Calibrators and wild-type patient HIV-1 RNA are co-amplified by NASBA in a single tube. (C) Four separate ECL detections are performed using specific ruthenium-labeled probes targeted to the altered internal calibrator sequences or the wild-type HIV-1 sequence. (D) Streptavidin paramagnetic beads with a bound HIV-1-specific biotinylated oligonucleotide capture the amplified targets. Voltage is applied, and ECL signals are read by the NucliSens Analyzer. (E) Wild-type HIV-1 RNA quantitation is based on unique calibration curves generated by the calibrators Qa, Qb, and Qc for each sample. (Figure reprinted with permission of bioMérieux, Inc., Durham, NC.)