Figure 1.

Defining and measuring early-stage phagocytosis and Rab recruitment (A) Schematic diagram of the progression of FcγR-mediated phagocytosis showing the classical enrichment of PI(4,5)P₂ followed by PI(3,4,5)P₃ on phagocytic cups and phagosomes. (B) Representative examples of the presence or absence of Rabs on phagocytic cups and phagosomes. Application of an external antibody against IgG-sRBC can distinguish the open phagocytic cup (blue signal in External) from the closed phagosome (loss of blue signal). These parameters correspond to a Venn diagram on the right where percentages of phagosome populations are quantified and classified into their corresponding areas in the Venn diagram (green shadings).