CD11b+ CD11c+ dendritic cells were enriched from WT or Rab39a KO spleens via magnetic negative selection. Cells were fed with 3 µm magnetic beads conjugated to Alexa fluor dye. After 4 hours, cells were harvested and resuspended in 1 mg/ml Trypan blue to quench fluorescence of uneaten beads. Cells were run for flow cytometry to measure phagocytosis. The ratio of KO cells with beads / WT cells with beads was then obtained. Graphs show three independent experiments and p values were calculated using two-tailed ratio-paired Student's t-test. Error bars show SD between experiments. 