• Product name
    Anti-Caldesmon antibody [E89]
    See all Caldesmon primary antibodies
  • Description
    Rabbit monoclonal [E89] to Caldesmon
  • Host species
  • Tested applications
    Suitable for: WB, IHC-P, ICC/IF, Flow Cyt, IPmore details
  • Species reactivity
    Reacts with: Mouse, Rat, Human
  • Immunogen

    Synthetic peptide within Human Caldesmon. The exact sequence is proprietary.

  • Positive control
    • NIH3T3,C6 and HeLa whole cell lysate (ab150035) and human uterus
  • General notes

    Our RabMAb® technology is a patented hybridoma-based technology for making rabbit monoclonal antibodies. For details on our patents, please refer to RabMab® patents

    This product is a recombinant rabbit monoclonal antibody.



Our Abpromise guarantee covers the use of ab32330 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

Application Abreviews Notes
WB 1/10000 - 1/20000. Detects a band of approximately 70 kDa (predicted molecular weight: 93 kDa).
IHC-P Use at an assay dependent concentration.
ICC/IF 1/250 - 1/500.
Flow Cyt 1/20.

ab172730 - Rabbit monoclonal IgG, is suitable for use as an isotype control with this antibody.

IP 1/80.


  • Function
    Actin- and myosin-binding protein implicated in the regulation of actomyosin interactions in smooth muscle and nonmuscle cells (could act as a bridge between myosin and actin filaments). Stimulates actin binding of tropomyosin which increases the stabilization of actin filament structure. In muscle tissues, inhibits the actomyosin ATPase by binding to F-actin. This inhibition is attenuated by calcium-calmodulin and is potentiated by tropomyosin. Interacts with actin, myosin, two molecules of tropomyosin and with calmodulin. Also play an essential role during cellular mitosis and receptor capping.
  • Tissue specificity
    High-molecular-weight caldesmon (isoform 1) is predominantly expressed in smooth muscles, whereas low-molecular-weight caldesmon (isoforms 2, 3, 4 and 5) are widely distributed in non-muscle tissues and cells. Not expressed in skeletal muscle or heart.
  • Sequence similarities
    Belongs to the caldesmon family.
  • Domain
    The N-terminal part seems to be a myosin/calmodulin-binding domain, and the C-terminal a tropomyosin/actin/calmodulin-binding domain. These two domains are separated by a central helical region in the smooth-muscle form.
  • Post-translational
    In non-muscle cells, phosphorylation by CDK1 during mitosis causes caldesmon to dissociate from microfilaments. Phosphorylation reduces caldesmon binding to actin, myosin, and calmodulin as well as its inhibition of actomyosin ATPase activity. Phosphorylation also occurs in both quiescent and dividing smooth muscle cells with similar effects on the interaction with actin and calmodulin and on microfilaments reorganization.
  • Cellular localization
    Cytoplasm > cytoskeleton. Cytoplasm > myofibril. On thin filaments in smooth muscle and on stress fibers in fibroblasts (nonmuscle).
  • Information by UniProt
  • Database links
  • Alternative names
    • CAD antibody
    • CALD 1 antibody
    • CALD1 antibody
    • CALD1_HUMAN antibody
    • Caldesmon 1 antibody
    • Caldesmon 1 Isoform 1 antibody
    • Caldesmon 1 Isoform 2 antibody
    • Caldesmon 1 Isoform 3 antibody
    • Caldesmon 1 Isoform 4 antibody
    • Caldesmon 1 Isoform 5 antibody
    • Caldesmon antibody
    • Caldesmon1 antibody
    • CDM antibody
    • H CAD antibody
    • HCAD antibody
    • L CAD antibody
    • LCAD antibody
    • MGC21352 antibody
    • NAG22 antibody
    see all


  • Anti-Caldesmon antibody [E89] (ab32330) at 1/20000 dilution + NIH3T3 cell lysate

    Predicted band size: 93 kDa
    Observed band size: 70 kDa
    why is the actual band size different from the predicted?

  • Immunocytochemistry/Immunofluorescence analysis of C6 (rat glioma) cells labelling Caldesmon with purified ab32330 at 1/500. Cells were fixed with 100% methanol. An Alexa Fluor® 488-conjugated goat anti-rabbit IgG (ab150077) at 1/1000 dilution was used as the secondary antibody. Nuclei couterstained with DAPI (blue). 

    Secondary Only Control: PBS was used instead of the primary antibody as the negative control. 

  • ab32300, at a 1/250 dilution, staining human Caldesmon in uterus tissue by Immunohistochemistry, Paraffin embedded tissue
  • ab32330, at a 1/250 dilution, staining human Caldesmon in HeLa cells by Immunofluorescence
  • Overlay histogram showing HeLa cells stained with ab32330 (red line). The cells were fixed with 4% paraformaldehyde (10 min) and then permeabilized with 0.1% PBS-Tween for 20 min. The cells were then incubated in 1x PBS / 10% normal goat serum / 0.3M glycine to block non-specific protein-protein interactions followed by the antibody (ab32330, 1/20 dilution) for 30 min at 22°C. The secondary antibody used was DyLight® 488 goat anti-rabbit IgG (H+L) (ab96899) at 1/500 dilution for 30 min at 22°C. Isotype control antibody (black line) was rabbit monoclonal IgG (0.5µg/1x106 cells) used under the same conditions. Acquisition of >5,000 events was performed. This antibody gave a significantly decreased signal in HeLa cells fixed with methanol (5 min)/permeabilized in 0.1% PBS-Tween used under the same conditions.

  • Fluorescent immunohistochemical analysis of paraffin-embedded human normal kidney vessels using ab32330. Green-Caldesmon red-PI

  • Fluorescent immunohistochemical analysis of paraffin-embedded human tissue using ab32330. Green-Caldesmon red-PI.

  • Fluorescent immunohistochemical analysis of paraffin-embedded human normal uterus tissue using ab32330. Green-Caldesmon red-PI.

  • Equilibrium disassociation constant (KD)
    Learn more about KD

    Click here to learn more about KD


This product has been referenced in:
  • Gonzalez JM  et al. Deep tissue analysis of distal aqueous drainage structures and contractile features. Sci Rep 7:17071 (2017). Read more (PubMed: 29213129) »
  • Shudo Y  et al. Isolation and trans-differentiation of mesenchymal stromal cells into smooth muscle cells: Utility and applicability for cell-sheet engineering. Cytotherapy 18:510-7 (2016). Read more (PubMed: 26971679) »
See all 17 Publications for this product

Customer reviews and Q&As

1-6 of 6 Abreviews or Q&A


I have attached an image of our Flow cytometry results with ab32330.

We used untreated HeLa cells as our negative control and Anisomycin-treated HeLa cells as our positive control. The primary dilution was 1:20. Both were permeabilized according to our standard protocol which is described below:

1. Solutions and Reagents
1.1. 1X PBS

1.2. Blocking buffer: 0.5% BSA in 1X PBS

1.3. 2% paraformaldehyde (1% solution - optional for storing samples)

1.4. 1X FACS permeabilizing solution (BD Biosciences cat. #340973)

1.5. Fluorescently-conjugated secondary antibody (various forms)

2. Protocol
2.1. Collect 1x106 cells/sample.

2.2. Wash cells once with blocking buffer.

2.3. Fix cells with 2% paraformaldehyde and incubate at room temperature for 10 min.

2.4. Wash cells once with blocking buffer.

2.5. Add 0.5 ml 1X FACS permeabilizing solution and incubate at room temperature for 10 min.

2.6. Wash cells once with blocking buffer.

2.7. Incubate cells in blocking buffer for 30 min at room temperature.

2.8. Add primary antibody at the appropriate dilution and incubate for 30 min at room temperature.

2.9. Wash twice with blocking buffer and incubate with fluorescently-conjugated secondary antibody for 30 min at room temperature.

2.10. Wash cells twice with blocking buffer.

2.11. Re-suspend cells in 1X PBS and analyze on flow cytometry. Samples can be kept in 1% paraformaldehyde at 4 °C overnight.

Please let me know if you have any additional questions.

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Thank you for your enquiry regarding ab32330.

Generally, antibodies can be stored at -20°C for several years if the storage buffer contains cryoprotective agent and the aliquot size is no smaller than 10 µl. Please always check the product datasheet for storage information.

However, I would like to emphasize that Abcam can only offer a full guarantee called Abpromise within 6 months of purchase.


If you need any further assistance in the future, please do not hesitate to contact me.

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Thank you for your reply and for kindly providing the further information.

We have one antibody for detection of Caldesmon which has been tested in flow cytometry and mouse, which I think is the one you already found:

Caldesmon antibody [E89] (ab32330)

The sequence we used to raise this antibody has 100% homology with all 6 Caldesmon isoforms. Depending on the level of expression in the customer's sample, they may be able to observe all 6.

Regrettably, this is therefore not specific for the smaller isoforms of the protein in this case and may not be what the customer is looking for.

If you have any further questions, please do not hesitate to contact me.

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Thank you for contacting us.

Checking the immunogen sequence for this antibody, this antibody is not specific to Caldesmon isoform 1. Based on the sequence, it might crossreact with isoform 1-6 of human Caldesmon protein.

We have two antibodies which react only with the heavy form/ Isoform 1:

ab50016 Anti-Caldesmon antibody [hHCD]

https://www.abcam.com/index.html?datasheet=50016 (or use the following: https://www.abcam.com/index.html?datasheet=50016).

and ab11013 Anti-Caldesmon antibody [CALD 5]

https://www.abcam.com/index.html?datasheet=11013 (or use the following: https://www.abcam.com/index.html?datasheet=11013).

I hope this information is helpful to you. Please do not hesitate to contact us if you need any more advice or information.

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Thank you for contacting us. Our source for this antibody confirms that the antibody does recognize a 120-150 kDa protein in smooth muscle samples. They do not, have a blot image, however. Please do not hesitate to contact us if you need any more advice or information.

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Thank you for your patience. The isotype of the anti-Caldesmon antibody is simply rabbit IgG. In immunology, no specific isotype has been determined for rabbits. It is only known for human and mouse. I hope this information is helpful to you. Please do not hesitate to contact us if you need any more advice or information.

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