Fig. 6. Colloidal gold labeling of the subunit of IL-2R reveals receptor intermixing after cell fusion. Kit225 K6 cells were labeled with anti-Tac antibodies against the IL-2R subunit. Two samples of these cells were separately labeled with 10 and 30 nm colloidal gold beads, and fused with PEG. Samples were taken at 0 minutes (A) and 80 minutes (B) after cell fusion. (C) Nonfused Kit225 K6 cells labeled with both 10 and 30 nm colloidal gold beads. Bar, 200 nm.