Figure 4.

Immunogold-localization of Sac3 in ECFP-Sac3 cells. (A) Triton X-100–extracted spheroplasts from ECFP-Sac3 cells were preimmunolabeled with a polyclonal anti-GFP antibody directly conjugated to 8-nm colloidal gold. Shown is a view along a cross-sectioned nuclear envelope stretch with labeled NPCs (arrows, top), and a gallery of selected samples of gold-labeled NPC cross sections (bottom). The anti-GFP antibody labeled exclusively the cytoplasmic periphery of the NPC. c, cytoplasm; n, nucleus. Bars, 100 nm. (B) Quantitative analysis of the gold particles associated with the NPC. Fifty-two gold particles were scored.