Labeled Tubulin-Alexa Fluor(R) 488

Source: Bovine Brain Material Labeled Tubulin-Alexa Fluor(R) 488 is generated by reacting Alexa Fluor(R) 488 NHS Ester (Thermo Fisher A20100) with Cycled Tubulin(TM) (Cat. No. PUR-032005), thereby covalently linking the dye to random tubulin surface lysines. Cycled Tubulin(TM) is >99% pure and polymerization competent. These properties are maintained during the labeling process by reacting Cycled Tubulin(TM) 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. The product is cryopreserved at 20 mg/ml in 50 mM K-Glutamate and 0.5 mM MgCl2 (pH=7.0). Activity When supplemented with guanosine (GTP or GMPCPP) and warmed to 37°C, Labeled Tubulin-Alexa Fluor(R) 488 will polymerize into MTs when above its critical concentration. It is recommended to combine Labeled Tubulin-Alexa Fluor(R) 488 with unlabeled tubulin at a ratio of 1:9 to a total tubulin concentration of 2 mg/ml. Cycled Tubulin (Cat. No. PUR-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. Uses Labeled Tubulin-Alexa Fluor(R) 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