Recombinant viruses containing the Gag and Pol domains from HIV-1 subtypes B and C do not have differences in RNA incorporation and GagPol processing. A - Quantitation of viral genomic RNA in virus particles. Virus particles were purified from the culture media of 293T/17 cells transfected with molecular clones of viruses at 48 h post-transfection, treated with DNase I RNase free for 2 h and concentrated by centrifugation through 30% sucrose. RNA was isolated from p24CA-normalized virus particles, subjected to the reverse transcription with oligo-dT primer and then to quantitative real-time PCR with the primer set specific for positive-strand HIV-1 DNA. The data of analysis of three independent viral preparations were quantified. Each point represents mean RNA copy number ± SD per 1 ng of p24CA in virus sample. B - Processing of Pr160GagPol polyprotein-precursor in the virus particles. The virus particles harvested from culture media of transfected 293T/17 cells and purified as in A were analyzed by Western blotting using the antibodies indicated in Materials and Methods. C - Quantification of Western blotting results. Western blotting data from two independent experiments were quantified using ImageJ software. Results show mean grey values of the bands ± SE and are presented as percentage of p24CA in each virus sample.