Directionality of brain microtubule assembly in vitro

UMMS Affiliation

Department of Cell Biology



Document Type



Animals; Autoradiography; Brain; Brain Chemistry; Chickens; Electrophoresis, Polyacrylamide Gel; Leucine; Microscopy, Electron; Microtubules; Staining and Labeling; Tritium; Viscosity


Chicks were injected intra-cerebrally with [(3)H]leucine, and (3)H-labeled microtubules were assembled in vitro in the brain supernatants. Pieces of these (3)H-labeled microtubules were then incubated with unlabeled brain tubulin subunits under conditions where the subunits assembled onto the labeled pieces. Electron microscopic autoradiography of the negatively-stained microtubules showed all of the radioactivity at one end of the tubules as they increased in length. This clearly demonstrated that the microtubules of brain in this in vitro system were being assembled unidirectionally.

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Citation: Proc Natl Acad Sci U S A. 1974 May;71(5):1710-4.

Related Resources

Link to Article in PubMed

Journal Title

Proceedings of the National Academy of Sciences of the United States of America

PubMed ID