Fig. 2. Scanning near-field optical and confocal microscopical images of PEG-fused cells. Cells were separately labeled with two different Fabs tagged with different fluorescent dyes. These samples were subsequently fused, and incubated at 37°C, except for D where incubation was on ice. Intermixing of the fluorescence in the two different channels was monitored using SNOM (A-F) and confocal (G-H) microscopy. The two images collected in the two fluorescence channels were superimposed on each other. The two signals are displayed in green and red, respectively. (A) Kit225 K6 cells, Cy3-IL-2R (green), Cy5-IL-2R (red), 0 minutes after fusion. (B) Kit225 K6 cells, Cy3-IL-2R (green), Cy5-IL-2R (red), 80 minutes after fusion. (C) JY cells, F-MHC-I (green), R-MHC-I (red), 80 minutes after fusion. (D) JY cells, F-MHC-I (green), R-MHC-I (red), 80 minutes after fusion, incubation on ice. (E) Kit225 K6 cells, Cy3-CD48 (green), Cy5-CD48 (red), 80 minutes after fusion. (F) Kit225 K6 cells, Cy3-TrfR (green), Cy5-TrfR (red), 80 minutes after fusion. (G) JY cells, F-MHC-I (green), R-MHC-I (red), 0 minutes after fusion, (H) JY cells, F-MHC-I (green), R-MHC-I (red), 80 minutes after fusion. Image size: A-F, 15x15 µm; G-H, 20x20 µm.