Fig. 4. Overexpression of full-length C-Nap1 causes patch formation. U2OS cells were transiently transfected with full-length C-Nap1 and, 24 hours later, processed for immunofluorescence or immunoelectron microscopy with C-Ab. For immunofluorescence microscopy (A), cells were fixed with methanol; for immunoelectron microscopy (B) cells were fixed with 3% paraformaldehyde/2% sucrose. C-Nap1 overexpression resulted in the formation of single (a) or multiple (b) patches. The arrowhead in Ab points to the patch containing the centrosome, as determined by counter-staining with anti--tubulin antibodies (not shown). Bars, 10 µm (Ab); 250 nm (Bb).