Your questions answered by the experts from PurSolutions.
What is the difference between Cycled Tubulin and Lyophilized Tubulin?
PurSolutions Cycled Tubulin and Lyophilized Tubulin products differ in their isolation method, storage method, and pricing. Lyophilized Tubulin is isolated by selective precipitation and subsequently lyophilized, while Cycled Tubulin is isolated by successive rounds of polymerization and depolymerization and subsequently cryopreserved. In general, PurSolutions recommends Cycled Tubulin for use in fluorescence-based assays and Lyophilized Tubulin for use in turbidity-based applications. Both products are isolated from bovine brain and guaranteed >99% pure.
Are your tubulin products cycled?
PurSolutions’ Cycled Tubulin is isolated by two rounds of polymerization and subsequent depolymerization. The Labeled Tubulin products on the other hand are derived from Cycled Tubulin and subjected to an addition two rounds of polymerization and subsequent depolymerization during the labeling process. PurSolutions’ Lyophilized Tubulin product is isolated by selective precipitation instead of cycling, and is therefore likely comprised of different tubulin isotypes than Cycled Tubulin and its Labeled Tubulin derivatives.
How should I store and handle tubulin products?
Cryopreserved reagents including Cycled Tubulin and Labeled Tubulin products are shipped on dry ice and stored at -80°C. When ready to use, thaw these reagents quickly in a 37°C water bath followed by immediate placement on ice. Multiple freeze/thaw cycles should be avoided (see below for more information). Lyophilized Tubulin is shipped and stored at ambient temperatures with moderate humidity control measures. Upon reconstitution, Lyophilized Tubulin should be placed on ice. Note that our lyophilized products have a protein to powder ratio of 1:2 (i.e. 1 mg tubulin = 3 mg powder). Comprehensive instructions for product storage and handling are included with every shipment.
Can I freeze/thaw tubulin products?
Cryopreserved reagents can undergo one freeze/thaw cycle with minimum impact on activity. In order to maximize utility, we recommend thawing the product upon receipt (thaw quickly in a 37°C water bath followed by immediate placement on ice), aliquoting into experimental-sized batches (work on ice to keep cold), refreezing in liquid nitrogen, and storing at -80°C.
How do I use tubulin products?
Purified tubulin has a broad range of experimental applications including structural analysis by X-ray crystallography and electron microscopy, drug discovery by high-throughput screening, and in vitro biochemical and biophysical assays. We encourage users to access commonly used protocols on PurSolutions’ website for helpful tips.
Why do you offer multiple colors of fluorescently-labeled tubulin?
Depending on the experimental setup and microscopy system, a user may require a specific spectroscopic profile or desire to integrate tubulin of different colors (i.e. generation of polarity-marked microtubules).
What is the labeling stoichiometry of the Labeled Tubulin products?
Labeled Tubulin products are guaranteed to have a labeling stoichiometry ([dye]/[tubulin]) ranging from 0.5-1.5 as determined by spectroscopic analysis. Specific labeling stoichiometries are indicated on product labels.
What is the difference between Ultra-Pure Actin and Pure Actin?
PurSolutions’ Ultra-Pure Actin and Pure-Actin differ in their purity and pricing. Both are extracted from rabbit skeletal muscle using an adaptation of the method of Spudich and Watt (1971) and lyophilized by an adaptation of the method of Dráberová et al. (2010). Ultra-Pure Actin is >99% pure and >90% active, while Pure Actin is >90% pure and >80% active. Activity is assessed by a pelleting assay.
How should I store and handle actin products?
PurSolutions’ actin products are shipped and stored at ambient temperatures with moderate humidity control measures. Actin products should immediately be placed on ice upon reconstitution. Note that our lyophilized products have a protein to powder ratio of 1:2 (i.e. 1 mg actin = 3 mg powder). Comprehensive instructions for product storage and handling are included with every shipment.
How do I use actin products?
Purified actin has a broad range of experimental applications including antibody generation, structural analysis by X-ray crystallography and electron microscopy, drug discovery by high-throughput screening, and in vitro biochemical and biophysical assays. We encourage users to access commonly used protocols on PurSolutions’ website for helpful tips.
How is PurSolutions different from the competition?
There are two overarching principles that separate PurSolutions from the competition. The first is our focused product line. By concentrating their efforts on purified tubulin and actin products, PurSolutions is able to produce reagents that boast the highest purity, activity, and batch to batch consistency in the market. Second, in contrast to many other suppliers, PurSolutions’ manufacturing facility enable them to fill custom requests and ensure customer satisfaction. These assets give PurSolutions’ unmatched control over product quality, consistency, and turn-around. Ultimately, by offering trusted products with outstanding customer service, PurSolutions aims to accelerate cytoskeletal research and drug discovery efforts.