Biotinylated microtubules bound to the surface of a streptavidin-coated flow cell. Microtubules were polymerized at 2 mg/ml [tubulin] with Labeled Tubulin-Biotin-XX (Cat. No. 033305), Labeled Tubulin-Alexa Fluor® 647, and Cycled Tubulin™ (Cat. No. 032005) at a 0.5:1:10 ratio and stabilized with GMPCPP. Image acquired on a widefield fluorescence microscope.


Catalog Number: 033305
Source: Bovine Brain

Labeled Tubulin-Biotin-XX is generated by reacting Biotin-XX succinimidyl ester with Cycled Tubulin (Cat. No. 032005), thereby covalently linking the biomolecule to random tubulin surface lysines. Cycled Tubulin is >99% pure and polymerization competent. These properties are maintained during the labeling process by reacting Cycled Tubulin with the reactive biotin in its polymerized form and subjecting it to a final polymerization/depolymerization cycle. The final product demonstrates an affinity toward streptavidin-coated beads (Figure 1) and streptavidin-coated coverslips (Figure 2). Specific labeling stoichiometries are indicated on the product label. The product is cryopreserved at 20 mg/ml in 50 mM K-Glutamate and 0.5 mM MgCl2 (pH=7.0).

Activity and Applications
Labeled Tubulin-Biotin-XX will polymerize into microtubules when supplemented with GTP, warmed to 37˚C, and kept above its critical concentration. Biotinylated tubulin is suitable for use in a variety of experimental applications, and can be combined with other labeled or unlabeled tubulin (Cycled Tubulin | Cat. No. 032005) in generating microtubules in vitro. Visit our protocols page for common microtubule polymerization protocols, including the generation of short, rigid microtubules stabilized by GMPCPP or long, flexible microtubules stabilized by taxol.

  • optical traps and molecular tweezers
  • single molecule kinesin motor assays
  • tubulin affinity columns
  • in vitro nanoscale devices

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Figure 1: Labeled Tubulin-Biotin-XX binds to streptavidin-coated beads. Coomassie G250-stained protein gel of unbound and bound fractions of tubulin samples incubated with Dynabeads® M-280 Streptavidin (Thermo Fisher 11205D). Cycled Tubulin serves as the non-biotinylated negative control. Labeled Tubulin-Biotin-XX fractionates with the streptavidin-coated beads.

Figure 2: Labeled Tubulin-Biotin-XX binds to streptavidin-coated coverslips. Fluorescent images of microtubules incubated in streptavidin-coated flow cells. Microtubules were polymerized with 1.8 mg/ml Cycled Tubulin and 0.2 mg/ml Labeled Tubulin-Alexa Fluor® 647 +/- 0.05 mg/ml Labeled Tubulin-Biotin-XX. Microtubules polymerized with Labeled Tubulin-Biotin-XX are bound to the flow-cell surface.