Figure 6.

Comparing direct and indirect staining methods in flow virometry to label HIV Env. Indirect staining of HIV_IIIB propagated in H9 CD4⁺ T cells with unlabeled primary anti-gp120 antibodies (PGT145 and PG9), and a PE-conjugated secondary antibody (top row). Direct staining of the same HIV_IIIB virus stocks using PE-labelled PGT145 and PG9 antibodies (bottom row). Positive staining is shown in the upper gate, while background levels fall within the lower gate. Median PE MESF values that were generated from all virus events within the merged upper and lower gates are enumerated on the plots.