hMB11 staining in neurons. (A and B) Staining with hMB11antibody of GTP-tubulin (green) at stage 2–3 (A) and stage 4 (B). Cells were counterstained with anti-MAP2 antibody (red). At stage 2, the hMB11 stain was biased among neurites (arrows). At stage 3, hMB11 stains the axon (arrow). (C) 100 nM paclitaxel was added. Note that paclitaxel treatment caused accumulation of GTP-tubulin in both axons and dendrites. Bars, 10 µm. (D, top) Double-label immunoelectron microscopy of axons with EB1 (10 nm) and hMB11 (5 nm). Orange circles on the left indicate patchy localization of 5-nm and 10-nm gold on MTs. The right shows the same view without circles. The middle shows the dendrite domain of the same neuron. The bottom shows control staining with a pan-MT antibody (DM1A; 10 nm colloidal gold). (E) Quantification of the axonal and dendritic staining of MB11 at stage 4. For dendrite staining, the highest fluorescence intensity was measured in dendrites (n = 72). For axonal staining, the highest fluorescence intensity was measured between the cell body and the axonal position at the same distance from the cell body with adjacent dendrites. Error bars indicate SEM. (F) Quantification of D. The number of 5-nm and 10-nm colloidal gold particles per axonal and dendrite area was counted (white column, 10 nm; black column, 5 nm). n = 14 (axons) and n = 6 (dendrites).