Skip to main content

Key Product Details

Species Reactivity

Human, Mouse, Rat, Porcine, Baboon, Bovine, Canine, Chicken, Feline, Goat, Guinea Pig, Monkey, Rabbit, Sheep


Flow (Intracellular), Flow Cytometry, Immunocytochemistry/ Immunofluorescence, Immunohistochemistry, Immunohistochemistry-Frozen, Immunohistochemistry-Paraffin, Immunoprecipitation, Simple Western, Western Blot



Antibody Source

Monoclonal Mouse IgG2a Kappa Clone # 1A4/asm-1


BSA Free


1.0 mg/ml

Product Summary for alpha-Smooth Muscle Actin Antibody (1A4/asm-1) - BSA Free


Alpha-Smooth Muscle Actin Antibody (1A4/asm-1) is made to the N-Terminal decapeptide of Alpha smooth muscle isoform of actin and conjugated to KLH.

Reactivity Notes

Feline reactivity reported from a verified customer review.




Actin is a major component of the cytoskeleton and is present in most cell types. This MAb is highly specific to actin from smooth muscles. Its epitope lies in the first four N-terminal amino acids. This MAb does not stain cardiac or skeletal muscle; however, it does stain myofibroblasts and myoepithelial cells. This antibody could be used together with anti-muscle specific actin and myogenin in making a diagnosis of smooth muscle and skeletal muscle tumors. In most cases of rhabdomyosarcoma, this antibody yields negative results whereas anti-muscle specific actin and myogenin are positive. Leiomyosarcomas are positive only with anti-muscle specific actin and anti-smooth muscle actin and are negative with anti-myogenin.


Leiomyosarcoma Marker






IgG2a Kappa

Theoretical MW

42 kDa.
Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.

Scientific Data Images for alpha-Smooth Muscle Actin Antibody (1A4/asm-1) - BSA Free

Western Blot Detection of alpha-Smooth Muscle Actin in Human Heart Tissue and iBJ6 hiPSCs

Western Blot Detection of alpha-Smooth Muscle Actin in Human Heart Tissue and iBJ6 hiPSCs

Western blot shows lysates of human heart tissue and iBJ6 human induced pluripotent stem cell line undifferentiated or cardiac differentiated. PVDF membrane was probed with 0.25 ug/mL of Mouse Anti-alpha-Smooth Muscle Actin Monoclonal Antibody (Catalog # NBP2-33006) followed by HRP-conjugated Anti-Mouse IgG Secondary Antibody (Catalog # HAF018). The observed molecular weight was detected for alpha Smooth Muscle Actin at approximately 40 kDa (as indicated). This experiment was conducted under reducing conditions.
Immunohistological Imaging of alpha-Smooth Muscle Actin in Frozen Feline Tissue

Immunohistological Imaging of alpha-Smooth Muscle Actin in Frozen Feline Tissue

Feline tissue stained with alpha-Smooth Muscle Actin Antibody at dilution of 1:600. Vascular wall was stained. IHC image submitted by a verified customer review.
Simple Western Analysis of alpha-Smooth Muscle Actin in Aorta Lysate

Simple Western Analysis of alpha-Smooth Muscle Actin in Aorta Lysate

Simple Western lane view shows a specific band for an observed molecular weight at ~45 kDa for alpha-Smooth Muscle Actin in 0.2 mg/ml of h. Aorta lysate. This experiment was performed under reducing conditions using the 12-230 kDa separation system.

Applications for alpha-Smooth Muscle Actin Antibody (1A4/asm-1) - BSA Free

Recommended Usage

Flow Cytometry

0.5-1ug/million cells

Immunocytochemistry/ Immunofluorescence









0.5-1ug/500ug protein lysate

Simple Western

10 ug/ml

Western Blot

Please Note: Optimal dilutions of this antibody should be experimentally determined.

Reviewed Applications

Read 3 reviews rated 4.7 using NBP2-33006 in the following applications:

Published Applications

Read 52 publications using NBP2-33006 in the following applications:

Formulation, Preparation, and Storage


Protein A purified




BSA Free


0.02% Sodium Azide


1.0 mg/ml


The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

Stability & Storage

Store at -20C.

Background: alpha-Smooth Muscle Actin

Actin proteins are highly conserved in eukaryotic cells and are involved in cell motility, structure and integrity. Actin and myosin are involved in a myriad of cellular processes including locomotion, secretion, cytoplasmic streaming, phagocytosis and cytokinesis. Actin filaments, along with microtubules, comprise a major component of the cytoskeleton and play essential roles in regulating cell shape and movement. Actin has been found to be expressed in at least six isoforms, each encoded by a separate gene and expressed in a developmentally regulated and tissue-specific manner. Alpha, beta and gamma actin isoforms have been identified. Alpha actins are a major constituent of the contractile apparatus, whereas beta and gamma actins are involved in the regulation of cell motility.

ACTA2 encodes alpha Smooth Muscle Actin and is also known as alpha-actin, alpha-actin-2, aortic smooth muscle or alpha smooth muscle actin (alpha-SMA, SMactin, alpha-SM-actin, ASMA). Alpha Smooth Muscle Actin is frequently used as a marker of smooth muscle differentiation and has a theoretical molecular weight of 42 kDa. Smooth muscle alpha actin is one of a few genes whose expression is predominantly expressed in vascular smooth muscle cells that is used to study myofibroblasts and fibrosis (1). Excessive accumulation of alpha smooth muscle actin-positive (ACTA2+) activated myofibroblasts is observed in Idiopathic pulmonary fibrosis (2). Expression of smooth muscle alpha actin is regulated by cell proliferation and is altered in pathological conditions including atherosclerosis and is common in metastatic cancers (1,3).


1. Chakraborty, R., Saddouk, F. Z., Carrao, A. C., Krause, D. S., Greif, D. M., & Martin, K. A. (2019). Promoters to Study Vascular Smooth Muscle. Arterioscler Thromb Vasc Biol, 39(4), 603-612. doi:10.1161/atvbaha.119.312449

2 .El Agha, E., Moiseenko, A., Kheirollahi, V., De Langhe, S., Crnkovic, S., Kwapiszewska, G., . . . Bellusci, S. (2017). Two-Way Conversion between Lipogenic and Myogenic Fibroblastic Phenotypes Marks the Progression and Resolution of Lung Fibrosis. Cell Stem Cell, 20(2), 261-273.e263. doi:10.1016/j.stem.2016.10.004

3. Chen, Y. C., Gonzalez, M. E., Burman, B., Zhao, X., Anwar, T., Tran, M., . . . Kleer, C. G. (2019). Mesenchymal Stem/Stromal Cell Engulfment Reveals Metastatic Advantage in Breast Cancer. Cell Rep, 27(13), 3916-3926.e3915. doi:10.1016/j.celrep.2019.05.084

Long Name

Actin, Alpha 2, Smooth Muscle, Aorta

Alternate Names

AAT6, ACTA2, Actin alpha 2, ACTSA, ACTVS, alphaSmooth Muscle Actin, MYMY5, SMA, 1a4 sma, 1a4 smooth muscle actin, alpha sma 1a4, sma 1a4

Gene Symbol



Product Documents for alpha-Smooth Muscle Actin Antibody (1A4/asm-1) - BSA Free

Certificate of Analysis

To download a Certificate of Analysis, please enter a lot number in the search box below.

Product Specific Notices for alpha-Smooth Muscle Actin Antibody (1A4/asm-1) - BSA Free

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Primary Antibodies are guaranteed for 1 year from date of receipt.


FAQs for alpha-Smooth Muscle Actin Antibody (1A4/asm-1) - BSA Free

Showing  1 - 1 of 1 FAQ Showing All
  • Q: Which antibodies would you recommend for the best performance in IHC?

    A: NB300-978, NBP1-30894, NBP2-22120, NBP2-32808, NBP2-33006, and NBP2-34522 have the broadest IHC applications, as they additionally list IHC-Paraffin and IHC-Frozen. To narrow the list down further, we would recommend using either NB300-978 or NBP2-33006 since these products have the most ratings and cited publications for use in IHC methods. NB300-978 has IHC-Free-Floating listed as an application as well.

Showing  1 - 1 of 1 FAQ Showing All