Pure Actin

Extracted from rabbit muscle to >90% and lyophilized for storage at room temperature.

Product: Pure Actin

Pure Actin Tube

Product Specifications:

Catalog Number: 190101
Purity: >90%
Source: rabbit skeletal muscle
Molecular Weight: ~43 kDa
Form: desiccated powder (1 mg actin protein is supplied as 3 mg powder with extra mass attributed to trehalose, a lyoprotectant)
Buffer Conditions Upon Reconstitution: 2 mM Tris-HCl, 0.2 mM CaCl2, 0.2 mM ATP, 1 mM DTT, and 0.25 M Trehalose (pH 8.0)
Shipping: shipped at ambient temperatures
Storage Conditions: store in a cool, dry environment
Shelf Life: check product label for expiration date


Pure Actin is extracted from rabbit skeletal muscle using an optimized version of the method of Spudich and Watt (1971) and lyophilized by an adaptation of the method of Dráberová et al. (2010). The resulting actin protein is >90% pure (Figure 1) and >80% polymerization competent (Figure 2). Possible contaminants include a-actinin (100 kDa). For actin protein of >99% purity, see our Ultra-Pure Actin product (Cat. No. 160101). Pure Actin is supplied as a white powder. When reconstituted with ultrapure water to 9 mg/ml, the buffer conditions are 2 mM Tris-HCl, 0.2 mM CaCl2, 0.2 mM ATP, 1 mM DTT, and 0.25 M Trehalose, pH 8.0. Note that 1 mg actin protein is supplied as 3 mg powder (extra mass attributed to trehalose, a lyoprotectant), and reconstitution/dilution should be based on the actin protein concentration.

Activity and Applications

Pure Actin will polymerize into filamentous F-actin when supplemented with KCl and MgCl2, and kept above its critical concentration. Pure Actin is suitable for use in a variety of cell-free experimental applications, and polymerization activity is detectable in fluorescence microscopy assays, turbidity assays, and ATPase assays. Visit our protocols page for common actin polymerization protocols.
  • antibody generation
  • drug discovery by high-throughput screening
  • in vitro biochemical and biophysical approaches
  • structural analysis by X-ray crystallography and electron microscopy

Greater Purity at a Better Price

Figure 1:

Pure Actin is >90% pure. Coomassie G250-stained protein gel of Pure Actin separated by SDS-PAGE.  The actin protein appears as the majority species migrating at ~43 kDa.  Possible contaminants include a-actinin (100 kDa) and are not in excess of 10%.  Molecular weight markers and loaded protein quantities are indicated.

Pure Actin Purity
Pure Actin Polymerization

Figure 2:

Pure Actin is >80% polymerization-competent.  Pure Actin polymerized in the absence (-PB) or presence (+PB) of Actin Polymer Buffer (10X, Cat. No. 000103; 50 mM KCl and 2 mM MgCl2) followed by centrifugation at 48k rpm (100k x g) for 1 hour.  Pellet (P) and supernatant (S) fractions were collected and subjected to SDS-PAGE and Coomassie G250-staining. >80% of Pure Actin was incorporated into filaments as determined by measuring the residual protein concentration in the supernatant fraction.

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