Microtubules motility

Tubulin polymerizes into microtubules, long fiber bundles that control a variety of cellular processes such as cell migration, cell division and axon guidance. Tubulin is a heterodimer of an alpha and a beta form.

Polarity of the protofilament is a key feature for microtubule functioning, in particular for direction-dependent cellular events.

Microtubules Motility assay

To determine whether a protein or compound alters kinesin or dynein-microtubule mobility or to test other proteins for microtubule mobility, the Kinesin Motility Assay Biochem Kit (Cat nr BK027) is a fluorescence based motility assay.


Kinesin or dynein motors are coupled to the surface of a microscope perfusion chamber (kinesin heavy chain motor domain is included in the kit as a positive control) and fluorescent microtubules are added. The motor-induced motility of the microtubules can be monitored and measured in a fluorescence microscope.

Learn more about the kit (Cat nr BK027) and its contents here.

Example results

The motility of microtubules in a kinesin heavy chain coated chamber was followed with time lapse microscopy (Figure).

Microtubule Motility Assay. The field was selected to show a sparse area of MT coverage in order to allow clear visualization of MT motility. Each frame represents a 5 min time-point, from 0 to 15 min. The position of each MT at time zero is marked by an arrow. The arrow position remains identical in each frame to serve as a reference point for MT movement. To obtain an average MT velocity, we recommend measure motility of approximately 30 - 50 individual MTs.

Fluorescent tubulin

Fluorescently labeled tubulin is useful for the study of microtubule dynamics by allowing one to follow the fate of injected tubulin in vivo. Fluorescent tubulin also has applications for in vitro assays, e.g., microtubule motor assays.

     Labeled Tubulin Source Purity Cat nr
     AMCA labeled tubulin Porcine brain >99% TL440M
     HiLyteFluor 488 labeled tubulin Porcine brain >99% TL488M
     TRITC Rhodamine labeled tubulin Porcine brain >99% TL590M
     X-Rhodamine labeled tubulin Bovine brain >99% TL620M
     HiLyteFluor 647 labeled tubulin Porcine brain >99% TL670M
     Biotin labeled tubulin Porcine brain >99% T333P
     Biotin Cancer labeled tubulin HeLa cells >90% H003