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  • F3777 - Monoclonal Anti-Actin, α-Smooth Muscle - FITC antibody produced in mouse

F3777 Sigma-Aldrich

Monoclonal Anti-Actin, α-Smooth Muscle - FITC antibody produced in mouse

clone 1A4, purified immunoglobulin, buffered aqueous solution

Synonym: Monoclonal Anti-Actin, α-Smooth Muscle, SMA

  •  NACRES NA.41



Related Categories AC-AC, Alphabetical Index, Antibodies, Antibodies against Proteins, Bioactives, Markers, and Receptors for Stem Cell Biology, Antibodies against Proteins/Bioactives/Markers/Receptors for Stem Cell Biology,
conjugate   FITC conjugate
clone   1A4, monoclonal
biological source   mouse
application(s)   immunohistochemistry (formalin-fixed, paraffin-embedded sections): 1:500 using human tonsil or appendix
species reactivity   human, frog, sheep, chicken, goat, bovine, rat, guinea pig, mouse, canine, rabbit, snake
mol wt   antigen ~42 kDa
form   buffered aqueous solution
shipped in   dry ice
storage temp.   −20°C
antibody form   purified immunoglobulin
isotype   IgG2a
antibody product type   primary antibodies
UniProt accession no.   P62736
Gene Information   human ... ACTA2(59)
mouse ... Acta2(11475)
rat ... Acta2(81633)


General description

The antibody (also known as anti-α-Sm-1) is specific for the single isoform of α-smooth muscle actin. It reacts specifically with α-smooth muscle actin in immunoblotting assays and labels smooth muscle cells in frozen or formalin-fixed, paraffin-embedded tissue sections.

α-smooth muscle actin, a smooth muscle cell-specific protein, is also known as aortic smooth muscle or a smooth muscle actin (α-SMA, SMactin, α-SM-actin, ASMA). It belongs to the actin family.It is predominantly found in cells of the smooth muscle lineages. It has been reported that α-smooth muscle actin was also found in certain non-muscle cells, in particular fibroblasts i.e. myofibroblasts. Actin, a conserved eukaryotic protein, is the major cytoskeletal component and is expressed as six different isoforms in mammals and birds. It is mapped to human chromosome 10q23.31.

The antibody reacts with normal and neoplastic, human vascular and visceral smooth muscle cells. It reacts with normal myoepithelial cells, pericytes, eye lens cells, hair follicle cells and certain stromal cells in the intestine, testis, lymphoid organs, liver, ovary and bone marrow. The antibody also reacts with stromal myofibroblasts in hypertrophic scars, and in neoplastic tissues. α-smooth muscle actin is transiently co-expressed with sarcomeric α-actin during myogenesis in chicken and rat embryos. It was also found in the ventricular conducting tract of adult mammalian heart.


Monoclonal Anti-Actin, α-Smooth Muscle specifically recognizes the α-smooth muscle isoform of actin (42 kDa) by ELISA and immunoblotting. It does not react with the other major actin isoforms present in fibroblasts or epithelial cells (β and γ-cytoplasmic), striated muscle (α-sarcomeric), myocardium (α-myocardial), or γ-smooth muscle isoform.


N-terminal synthetic decapeptide of α-smooth muscle actin.


Immunocytochemistry was performed on smooth muscle cells from bovine aortas using the monoclonal anti-ACTA2 antibody. Cells were first grown on glass cover slips and fixed in 50% acetone/EtOH for 10 minutes at 4 degrees.

Monoclonal Anti-Actin, α-Smooth Muscle - FITC antibody is suitable for:
• immunohistochemical (IHC) staining of heart, lung, kidney, and liver of mice to examine the PHD2 deficiency in internal organs
• immunostaining to analyze vascular smooth muscle cells/pericytes development in platelet-derived growth factor (PDGFR) and PDGFR- β-/- embryos
• immunofluorescent analysis of implanted cells, frozen tissue samples to study the similar levels of expression of SMaA and SM-MHC as established primary SMC lines
• western blots of lens epithelial cells to determine the distribution of α-SMA expression in lens epithelial cell
• Immunohistochemical examination of lesion morphology
• flow cytometry
• immunohistochemistry, proliferation and TUNEL (terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling) assays
• immunocytochemistry

Paraffin embedded sections of rat testis tissue grafts were immunohistochemically stained with mouse monoclonal anti-smooth muscle actin.
IHC analysis of x-gal stained muouse cardiac tissue was performed using the primary antibody, mouse monoclonal anti-smooth muscle actin to identify myofibroblasts.

Physical form

Solution in 0.01 M phosphate buffered saline, pH 7.4, containing 1% bovine serum albumin and 15 mM sodium azide, as a preservative.

Storage and Stability

For continuous use, store at 2-8 °C for up to one month. For extended storage, freeze in working aliquots. Repeated freezing and thawing, or storage in "frostfree" freezers, is not recommended. If slight turbidity occurs upon prolonged storage, clarify the solution by centrifugation before use. Protect from prolonged exposure to light.


Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals.

Biochem/physiol Actions

Actin plays an important role in cell motility, structure and integrity. Smooth muscle actin-α (SMA)/ α2-smooth muscle actin (ACTA2) interacts with β-myosin heavy chain and helps in vascular smooth muscle cell contraction. The encoded protein modulates the expression of c-MET (tyrosine-protein kinase Met) and focal adhesion kinase (FAK) in human lung adenocarcinoma cells, which positively and selectively mediates tumor progression. Mutation in the gene expression leads to thoracic aortic aneurysms and dissections (TAAD).

Other Notes

To view an Actin antibody selection guide, please visit www.sigmaaldrich.com/actin.

Safety & Documentation

Safety Information

NONH for all modes of transport
WGK Germany 
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