Fig. 3.

Phagocytosis of red fluorescent C. albicans by J774 macrophages in real time. Red fluorescent C. albicans cells (strain SKY38) were added to J774 macrophages grown on coverslips in multiwell plates. Yeast cells were added at an MOI of ∼1 yeast cell per macrophage, and at various times after addition of yeast cells, CW (1 μg/ml) and PSA-FITC (20 μg/ml) were added to the culture medium to stain the surface of noningested yeast cells and macrophages, respectively. Cells were viewed by fluorescence microscopy directly, without washing, using RFP, GFP, and 4′,6-diamidino-2-phenylindole filter sets. Arrows denote RFP-positive internalized yeast cells that are inaccessible to staining with CW.