DC3.2-Rab39a-H2-Ld cells (Rab39a KO with dox-inducible Rab39a) were incubated with or without 1 µg/ml dox overnight to induce Rab39a expression. 1x106 cells were fed at 4 beads/cell of biotinylated-magnetic-beads for 4 hours. Magnetic bead phagosomes were isolated using the listed protocol. Phagosomes were washed, fixed, permeabilized and stained for Open (64-3-7) and Closed (30-5-7s) forms of H2-Ld. H2-Ld cell surface levels of KO and induced cells as in (A). 