Non-reducing SDS-PAGE and western blot analysis of gp140 expression following co-transfection of multiple <i>env</i> plasmids.

<p>Six flasks were transiently transfected with three different gp140 <i>env</i> plasmids. 1∶3x subtype A, 2∶3x subtype B, 3∶3xsubtype C, 4: subtypes A, B and C, 5: subtypes A, D and F, 6: subtypes B, C and F. (<b>A</b>) Detection of gp140 proteins in supernatant with anti-His₆, anti-FLAG and anti-HA antibodies. All three tags were detected for each of the six <i>env</i> combinations. (<b>B</b>) Detection of HA-tagged gp140 in transfection supernatant, after His₆-capture with Co²⁺ beads, and after FLAG-capture with anti-FLAG-tagged magnetic beads. The HA tag was detectable at all stages in all six transfections.