Actin protein ( >99% pure): human platelet

Actin protein (>99% pure): human platelet

Product Uses Include

  • Identification and characterization of non-muscle actin binding proteins
  • In vitro actin polymerization studies
  • Antibody standard for Western blot analysis

Non-muscle actin has been purified from human platelets. Each unit of platelets used in the preparation of non-muscle actin has been found to be non-reactive by an FDA approved test for HBsAg, HBcAb, HIV-1/2 ab, HIV-1 RNA, HTLV I/II ab, HCV ab, HCV RNA, and syphilis. Each unit of platelets has been ALT tested with results less than an established cutoff. The isotype composition of non-muscle actin is 85% β-actin and 15% γ-actin. Non-muscle actin has an approximate molecular weight of 43 kDa. The product is provided as a lyophilized white powder. The lyophilized protein is stable for 6 months when stored desiccated to <10% humidity at 4°C. The protein should be reconstituted to 10 mg/ml with distilled water.  It will then be in the following buffer: 5 mM Tris-HCl pH 8.0, 0.2 mM CaCl2, 0.2 mM ATP, 5% sucrose, and 1% dextran.

Protein purity is determined by scanning densitometry of Coomassie Blue stained protein on a 12% polyacrylamide gel. APHL99 consists of >99% pure non-muscle actin while APHL95 is >95% pure (see Figure 1).


   Figure 1: Figure 1. Purities of human platelet non-muscle actin protein. 100 µg of >99% pure (APHL99) and >95% pure (APHL95) non-muscle actin were run on SDS-PAGE gels and stained with coomassie blue. The arrow indicates actin protein (~43 kDa), the arrowhead a gelsolin contaminant (~90 kDa). The minor impurities in the purified actins are predominantly actin binding proteins such as gelsolin and α-actinin. Protein quantitation was determined with the Precision Red Protein Assay Reagent (Cat. # ADV02)

Biological Activity
The biological activity of muscle actinis determined by its ability to efficiently polymerize into filaments (F-actin) in vitro and separate from unpolymerized components in a spin down assay. Stringent quality control ensures that APHL99 produces >85% F-actin and APHL95 produces >75% F-actin in this assay.

For product Datasheets and MSDSs please click on the PDF links below.   For additional information, click on the FAQs tab above or contact our Technical Support department at


  • For a guide to performing actin polymerizations with this actin product please click here.

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Delaunay, Marion et al.AKAP2-anchored extracellular signal-regulated kinase 1 (ERK1) regulates cardiac myofibroblast migrationBiochimica et Biophysica Acta (BBA) - Molecular Cell Research2024ISSN 0167--4889
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Selvaraj, Muniyandi et al.Structural basis underlying specific biochemical activities of non-muscle tropomyosin isoformsCell reports2023ISSN 2211--1247
Puccini, Joseph et al.Cytoskeletal association of ATP citrate lyase controls the mechanodynamics of macropinocytosisProceedings of the National Academy of Sciences of the United States of America2023ISSN 1091-6490
Du, William W. et al.Nuclear Actin Polymerization Regulates Cell Epithelial-Mesenchymal TransitionAdvanced Science2023ISSN 2198--3844
Martin, Jose L. et al.Actin Isoform Composition and Binding Factors Fine-Tune Regulatory Impact of Mical EnzymesInternational Journal of Molecular Sciences 2023, Vol. 24, Page 166512023ISSN 1422--0067
Selvaraj, Muniyandi et al.Structural basis underlying specific biochemical activities of non-muscle tropomyosin isoformsCell Reports2023
Hamasaki, Eriko et al.The Lipid-Binding Defective Dynamin 2 Mutant in Charcot-Marie-Tooth Disease Impairs Proper Actin Bundling and Actin Organization in Glomerular PodocytesFrontiers in Cell and Developmental Biology2022ISSN 2296-634X
Tsai, Feng Ching et al.Activated I-BAR IRSp53 clustering controls the formation of VASP-actin–based membrane protrusionsScience Advances2022ISSN 2375-2548
Chen, Li et al.Differential N-terminal processing of beta and gamma actiniScience2022
La, The Mon et al.Dynamin 1 is important for microtubule organization and stabilization in glomerular podocytesFASEB Journal2020ISSN 1530-6860
Park, Jin Suk et al.Mechanical regulation of glycolysis via cytoskeleton architectureNature2020ISSN 1476-4687
Ergin, Volkan et al.Putative Coiled-Coil Domain-Dependent Autoinhibition and Alternative Splicing Determine SHTN1’s Actin-Binding ActivityJournal of Molecular Biology2020ISSN 1089-8638
Slater, Paula G. et al.XMAP215 promotes microtubule-F-actin interactions to regulate growth cone microtubules during axon guidance in Xenopus laevisJournal of cell science2019ISSN 1477--9137
Zhang, Shengnan et al.In-cell NMR study of Tau and MARK2 phosphorylated TauInternational Journal of Molecular Sciences2019ISSN 1422-0067
Figard, Lauren et al.Cofilin-Mediated Actin Stress Response Is Maladaptive in Heat-Stressed EmbryosCell Reports2019ISSN 2211-1247
Osório, Daniel S. et al.Crosslinking activity of non-muscle myosin II is not sufficient for embryonic cytokinesis in C. elegansDevelopment (Cambridge, England)2019ISSN 1477-9129
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 Question 1: Do you have pyrene-labeled non-muscle actin for use in a polymerization assay?

Answer 1:  Pyrene-labeled non-muscle actin has been shown to be unstable under normal storage conditions and was discontinued.  To examine the polymerization of unlabeled non-muscle actin, please click here for a polymerization protocol that uses an excess of unlabeled non-muscle actin (Cat# APHL99) + a small amount of pyrene-labeled muscle actin (Cat. # AP05).  The pyrene muscle actin will not polymerize efficiently on its own at the concentration used in this assay, so the reaction is dependent on unlabeled actin polymerization for F-actin formation In this way, the pyrene-labeled muscle actin is taken up and polymerized to serve as a reporter for polymerization of the unlabeled non-muscle actin that is present at a much greater concentration. 


Question 2:  Are the actin products shipped as pure G-actin or a mixture of G- and F-actin?

Answer 2:  Most of our actin proteins are sold in the monomer form (G-actin) because this is stable to freezing and lyophilization.  That being said, on the day of the experiment, we do recommend incubating the actin on ice for 60 min before beginning the experiment to depolymerize any actin oligomers that might have formed during storage.  Typically actin is first diluted to 0.4 or 0.2 mg/ml concentration and then this can be incubated on ice for 60 min to depolymerize any actin oligomers that might have formed.  If you are working with an actin concentration above 0.4 mg/ml, we recommend the ice incubation followed by a high-speed centrifugation (100,000 x g) for 60 min to pellet any actin oligomers that may not have depoymerized.  Remove the top 80% of the supernatant and use this as your G-actin stock.  We also provide pre-formed actin filaments (Cat. # AKF99) that are shipped lyophilized and upon resuspension, the filaments are ready for use and average 5-10 microns in length.


If you have any questions concerning this product, please contact our Technical Service department at