Microtubule Fine Structure

Recent studies have demonstrated the widespread occurrence of microtubules in the cytoplasm of both animal and plant cells (e.g., Burgos and Fawcett, 1955; Manton , 1959; Slautterback, 1963; Ledbetter and Porter, 1963). The microtubules have usually been examined in sectioned material after osmium tetroxide or glutaraldehyde fixation. Because of advantages in the negative staining technique, it seemed useful to study spread material after t reatment with phosphotungstate or uranyl solutions. The technique has yielded good results with microtubules, permit t ing study of their fine structure at high resolution.