The localization of tau proteins on the microtubule surface.

The localization of porcine brain tau factor on in vitro assembled microtubules has been carried out by immunoelectron microscopy, using affinity-purified antibodies and protein A-gold particles. A parallel experiment was done using antibody against microtubule associated protein 2 (MAP2) and also a double labelling experiment using both antibodies with different sized gold particles. Our results indicate that, within the limits of resolution imposed by immunolabelling, the distribution patterns of tau factor and MAP2 on the microtubule are indistinguishable.