Binding of C3dg-gold10 to the plasma membrane and tracing to endocytic compartments of Raji cells.

(A) C3dg-gold10 in close vicinity to a coated pit marked by an arrow (incubation for 7 minutes at 37°C); scale bar, 0.1 μm. (B, C) Within peripherally located intracellular vacuoles (7 minutes at 37°C); (B) Cryofixation; scale bar, 0.15 μm. (D) Irregularly shaped multivesicular body in the cell periphery (30 minutes at 37°C); scale bar, 0.15 μm. (E) Multivesicular body in the vicinity of the nucleus (120 minutes at 37°C); scale bar, 0.15 μm. (F) Multilaminar body (120 minutes at 37°C); scale bar, 0.15 μm. (G) Multivesicular/multilaminar body harboring aggregations of gold particles indicating flocculation caused by proteolysis of gold-coupled C3dg (note that such aggregations do not stain with anti-C3d; data not shown; incubation for 120 minutes at 37°C); scale bar, 0.15 μm.