Labeled Tubulin-Alexa Fluor® 488
Catalog Number: 048805
Source: Bovine Brain
Shipping: shipped on dry ice
Storage Conditions: store at -80˚C immediately
Form: green aqueous solution
Molecular Weight: ~110 kDa
Purity: >99% (SDS-PAGE)
Concentration: 20 mg/ml
Buffer Conditions: 50 mM K-Glutamate and 0.5 mM MgCl2 (pH 7.0)
Maximum Excitation/Emission: 494/517 nm
Labeling Stoichiometry: ~1.0 (check product label)
Shelf Life: check product label for expiration date
Taxol Stabilized Microtubules (long and flexible)
Taxol-stabilized microtubules at 5 mg/ml total tubulin protein with Labeled Tubulin-Alexa Fluor® 488 (Cat. No. 048805) and Cycled Tubulin™ (Cat. No. 032005) at a 1:5 ratio. Images acquired on a widefield fluorescence microscope. View protocol.
Labeled Tubulin-Alexa Fluor® 488 is generated by reacting Alexa Fluor® 488 succinimidyl ester with Cycled Tubulin™ (Cat. No. 032005), thereby covalently linking the dye 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 dye in its polymerized form and subjecting it to a final polymerization/depolymerization cycle. The final product displays maximum absorption at 280 nm and 494 nm, and a labeling stoichiometry ([dye]/[tubulin]) of ~1.0 as determined by spectroscopic analysis (Figure 1). Specific labeling stoichiometries are indicated on the product label. Labeled Tubulin-Alexa Fluor® 488 is commonly visualized with a FITC filter set with maximum excitation/emission wavelengths of 494/517 nm (see images above). 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-Alexa Fluor® 488 will polymerize into microtubules when supplemented with guanosine-5'-triphosphate (GTP), warmed to 37˚C, and kept above its critical concentration. Polymerization activity is detectable in a variety of experimental systems including fluorescence microscopy assays, turbidity assays, and GTPase assays. Labeled tubulin is suitable for use in a variety of fluorescent experimental applications including live cell injection, and can be combined with unlabeled tubulin in generating fluorescent microtubules in vitro. Cycled Tubulin™ (Cat. No. 032005) is highly recommended as the unlabeled tubulin source in order to minimize tubulin heterogeneity, as labeled tubulin products are derived directly from Cycled Tubulin™. 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.
The only green Alexa Fluor® - Tubulin Protein on the Market
Labeled Tubulin-Alexa Fluor® 488 displays maximum absorption at 280 nm and 494 nm. Spectroscopic analysis reveals a peak at 280 nm and 494 nm, indicating absorption by the tubulin protein and Alexa Fluor® 488 dye, respectively.