Quantitative analysis of reverse transcription of spliced and unspliced HIV RNAs within infected cells. The different RTion products were quantified in 25ng of cellular DNA samples and results derived from standard curves realized with pNL4.3 dilutions, were expressed as copy numbers (cps) in 105 cells. The GAPDH gene was monitored to control the input of cellular genomic DNA samples used in each assay. Reliability and specificity of the QPCR amplifications are illustrated with 5 × 105 cps of pNL4.3 plasmid. Since U3 and ssDNA targets occur twice in the pNL4.3 plasmid used for standard curve, the measured cps were multiplied by 2 to obtain the real number of target sequences in the corresponding sample. Results represent mean standard ± deviations of at least three independent experiments.