FIG. 3.

Gamma radiation of MAb-coated C. neoformans cells. Cryptococcal cells with induced capsule were incubated with different concentrations of MAb 18B7. Cells were then irradiated for 20 min and compared to untreated cells. An immunofluorescence assay to detect 18B7 was performed using a goat anti-mouse IgG1-FITC Ab. The cells were suspended in parallel in India ink suspension to visualize the capsule. For each irradiation time: left column, cells suspended in India ink; middle column, light microscopy; right column, 18B7 localization, same field as the middle column. Note how cells present some aggregation, due to the “sticky” properties of Abs. Bar, 5 μm.