Figure 2. Phagocytosis of live Borrelia burgdorferi by IDE12. IDE12 cells were incubated with viable borreliae for 24 hours, fixed, and the external borreliae stained with a FITC-conjugated anti-borrelia antibody. Phagocytosis by untreated cells was compared with cells treated with cytochalasin B, an inhibitor of phagocytosis. External, morphologically normal borreliae are adherent to cells in the FITC panel (arrowheads), while external and internal spirochetes and cell nuclei can be seen in the DAPI panel. Coiled spirochetes are seen inside the cells (arrows). Scale bar, 10 μm.