LABELED TUBULIN-ALEXA FLUOR® 488
Catalog Number: 048805
Source: Bovine Brain
Labeled Tubulin-Alexa Fluor® 488 is generated by reacting Alexa Fluor® 488 NHS Ester (Thermo Fisher A20100) 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 absorbance at 494 nm and a labeling stoichiometry ([dye]/[tubulin]) of 0.5-1.5 as determined by spectroscopic analysis (Figure 1). The product is cryopreserved at 20 mg/ml in 50 mM K-Glutamate and 0.5 mM MgCl2 (pH=7.0).
When supplemented with guanosine (GTP or GMPCPP) and warmed to 37°C, Labeled Tubulin-Alexa Fluor® 488 will polymerize into MTs when above its critical concentration. It is recommended to combine Labeled Tubulin-Alexa Fluor® 488 with unlabeled tubulin at a ratio of 1:9 to a total tubulin concentration of 2 mg/ml. 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.
Labeled Tubulin-Alexa Fluor® 488 is supplied for use in fluorescent experimental systems including:
- in vitro MT gliding assays and single molecule motor assays
- speckle microscopy and live cell injection
- in vitro nanoscale devices
Seeing is believing.
Figure 1: 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 tubulin and Alexa Fluor® 488, respectively. Spectroscopic analysis further reveals a labeling stoichiometry of 0.5-1.5. Specific labeling stoichiometries are indicated on the product label.