Genotypic analysis of HIV-1 Gag circulating recombinant forms (CRFs): Boot scanning analysis of HIV-1 Gag gene with CRFs. (A) isolate MBBL10; (B) isolate MBBL05; (C) isolate MBBL 04. Conditions used were the following: Window: 400 bp, step size: 40 bp, gapstrip: on, reps: 100, Kimura (2-parameter), T/t: 2.0.