• Product name

    Anti-IgA Secretory Component antibody [SC-05]
    See all IgA Secretory Component primary antibodies
  • Description

    Mouse monoclonal [SC-05] to IgA Secretory Component
  • Host species

  • Specificity

    ab3924 reacts with 80 kDa human secretory component glycoprotein (both free and bound in secretory IgA). The recognized glycoprotein is a specific membrane marker of glandular carcinomas.
  • Tested applications

    Suitable for: IHC-Fr, IP, WB, IHC-Pmore details
  • Species reactivity

    Reacts with: Human
  • Immunogen

    Full length native protein (purified) corresponding to Human IgA Secretory Component. Affinity-purified secretory component from human colostrum.

  • Positive control

    • Secretory mucosa of gastrointestinal and respiratory tract, epithelia of salivary glands, endometrium, endocervix, kidney, prostate, mammary gland.
  • General notes

    Examples of positive human tissues: secretory mucosa of gastrointestinal and respiratory tract, epithelia of salivary glands, endometrium, endocervix, kidney, prostate, mammary gland.


  • Form

  • Storage instructions

    Shipped at 4°C. Store at +4°C short term (1-2 weeks). Upon delivery aliquot. Store at -20°C or -80°C. Avoid freeze / thaw cycle.
  • Storage buffer

    pH: 7.40
    Preservative: 0.097% Sodium azide
    Constituent: PBS
  • Concentration information loading...
  • Purity

    Protein A purified
  • Purification notes

    Purified from hybridoma culture supernatant. Purity >95% by SDS-PAGE.
  • Primary antibody notes

    Examples of positive human tissues: secretory mucosa of gastrointestinal and respiratory tract, epithelia of salivary glands, endometrium, endocervix, kidney, prostate, mammary gland.
  • Clonality

  • Clone number

  • Isotype

  • Research areas


Our Abpromise guarantee covers the use of ab3924 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
IHC-Fr Use at an assay dependent concentration.
IP Use at an assay dependent concentration.
WB Use a concentration of 1 - 2 µg/ml. Detects a band of approximately 68 kDa (predicted molecular weight: 61 kDa). See Abreview. Use under non-reducing conditions.
IHC-P Use at an assay dependent concentration.


  • Relevance

    IgA has two subclasses (IgA1 and IgA2) and can be produced as a monomeric as well as a dimeric form. The IgA dimeric form is the most prevalent and is also called secretory IgA (sIgA). The secretory component of sIgA protects the immunoglobulin from being degraded by proteolytic enzymes, thus sIgA can survive in the harsh gastrointestinal tract environment and provide protection against microbes that multiply in body secretions. sIgA can also inhibit inflammatory effects of other immunoglobulins. Secretory component is a proteolytic cleavage product of the polymeric immunoglobulin receptor which remains associated with dimeric IgA in sero-mucus secretions. Polymeric IgA binds to the polymeric immunoglobulin receptor on the basolateral surface of epithelial cells and is taken up into the cell via transcytosis. The receptor-IgA complex passes through the cellular compartments before being secreted on the luminal surface of the epithelial cells, still attached to the receptor. Proteolysis of the receptor occurs and the dimeric IgA molecule, along with the secretory component, are free to diffuse throughout the lumen. Secretory components wrap around two IgA units joined by a J chain protein fragment, resulting in a >--< configuration, with each of the two antigen binding regions of the two constituent y-shaped antibodies exposed. One identified function of secretory components is to protect IgA antibodies from degradation by the gastric acids and enzymes of the digestive system. This property is especially important in the transfer of immune system components during breastfeeding.


  • All lanes : Anti-IgA Secretory Component antibody [SC-05] (ab3924) at 1 µg/ml

    Lane 1 : MCF7 (Human breast adenocarcinoma cell line) Whole Cell Lysate
    Lane 2 : MDA-MB-361 (Human breast adenocarcinoma cell line) Whole Cell Lysate Whole Cell Lysate

    Lysates/proteins at 10 µg per lane.

    All lanes : Goat Anti-Mouse IgG H&L (HRP) preadsorbed (ab97040) at 1/5000 dilution

    Developed using the ECL technique.

    Performed under reducing conditions.

    Predicted band size: 61 kDa
    Observed band size: 68 kDa
    why is the actual band size different from the predicted?
    Additional bands at: 38 kDa. We are unsure as to the identity of these extra bands.

    Exposure time: 20 minutes

    Secretory Component Glycoprotein contains a number of potential glycosylation sites (SwissProt) which may explain its migration at a higher molecular weight than predicted.
  • ab3924 staining IgA Secretory Component in human normal breast tissue by Immunohistochemistry (Frozen sections).Tissue was fixed in methanol, blocked using 10% serum for 5 minutes at 25°C and then incubated with ab3924 at a 1/100 dilution for 1 hour at 25°C. The secondary used was an undiluted HRP conjugated goat polyclonal.The images show stainings of normal breast glands from two different patients. The antibody mostly stains the apical/luminal region of luminal epithelial cells, but the intensity varies from patient to patient.

    See Abreview

  • Immunohistochemical analysis of Human breast cancer tissue, staining IgA Secretory Component with ab3924.

    Antigen retrieval was performed by heat mediation in a citrate buffer (pH 6). Tissue was blocked with 10% normal goat serum before incubating with primary antibody (1/50) for 2 hours at room temperature. Staining was primarily in the cytoplasm.


This product has been referenced in:

  • Heinbockel L  et al. Identification of novel target genes in human lung tissue involved in chronic obstructive pulmonary disease. Int J Chron Obstruct Pulmon Dis 13:2255-2259 (2018). Read more (PubMed: 30100715) »
  • Wu Q  et al. Extracellular matrix protein 1 is correlated to carcinogenesis and lymphatic metastasis of human gastric cancer. World J Surg Oncol 12:132 (2014). IHC-P ; Human . Read more (PubMed: 24779890) »
See all 7 Publications for this product

Customer reviews and Q&As

1-10 of 10 Abreviews or Q&A


I have had a look at the nature of this protein: Extracellular matrix protein 1 (http://www.uniprot.org/uniprot/Q16610)

Unfortunately, I do not think it is scientifically to detect only ECM1b without detecting ECM1a.

The difference between these two isoforms is that ECM1b lacks amino acids 237-361. Therefore, if you had an antibody targeting this region, it would detect ECM1a but not ECM1b. You however wouldn't be able to specifically detect ECM1b as all the amino acids present in this isoform are also present in ECM1a.

Read More


It appears that there is a nomenclature difference between your target of interest (secretory component) and our antibodies that are anti "secretory component glycoprotein" which is also referred to as "Extracellular matrix protein 1" and "secretory component p85"
Thus, it seems an anti-PIGR antibody would be more applicable for your needs. Even though an anti-PIGR antibody that only detects the cleaved secretory component without detecting uncleaved PIGR won't exist, we can find one that detects both cleaved secretory component and the uncleaved, full-length PIGR by choosing an antibody that recognizes aa 19-603 of PIGR. Our rabbit polyclonal anti-PIGR antibody that meets this requirement is listed below:

Read More


For ab3924, the links to the databases and target information mention "Extracellular matrix protein 1" which is an alternative name for "secretory component p85" and "secretory component glycoprotein" according to the uniprot file below:

Read More


Thank you for contacting us.

In general, the selection of the immunogen varies from antibody to antibody. Some antibodies are raised against synthetic peptides (based ona protein sequence which was derived originally from a DNA sequence), some against protein fragments and others against the full length protein (either purified or overexpressed in another organism) or a cell preparation.

Which specific antibody or protein target do you have in mind?

As for the anti-IgA antibodies - the immunogendepends on the antibody.

Please let me know more details about the products of your interest and I'd be happy to assist you further.

Read More


Thank you for contacting Abcam.

I am sorry to hear that Ab55676 has not performed well for you. Although the peptide sequence has excellent identity with the mouse homolog, this product is not guaranteed to work in mouse tissues. High background is a very common issue when working in tissues of the same species as the host speciesof the primary anti-body. These may be reduced by using a secondary antibody that has been pre-absorbed or by direct conjugation of your label to the primary antibody.

Our EasyLink conjugation kits offer an effective and simple way to directly conjugate labels to your primary antibody. More information may be found at the following link:


We have 12 secondary antibodies against mouse IgG1, they may be viewed at the following link:


Please let me know if you have any questions.

Read More
Immunohistochemistry (Frozen sections)
Human Tissue sections (Normal breast)
Normal breast
Blocking step
Serum as blocking agent for 5 minute(s) · Concentration: 10% · Temperature: 25°C

Abcam user community

Verified customer

Submitted Jan 04 2012


Thank you for contacting us. Unfortunately we do not have any specific information about the epitope of Anti-Secretory Component Glycoprotein antibody [SC-05] (ab3924). We do however know that the epitope recognised is reduction-resistant and present in both the free and Ig-bound secretory component. More precise information regarding the epitope is not known.   I hope this information has been of help. If you need any further information please let us know and we will try to assist you. 

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Thank you for your enquiry. Unfortunately the only information the originator of the antibody was able to provide was mostly on the datasheet: The antibody reacts with 80 kDa human secretory component glycoprotein (both free and bound in secretory IgA). Recognized glycoprotein is specific membrane marker of glandular carcinomas. I am sorry I could not be more helpful. Please do not hesitate to contact us if you need anything further.

Read More


Thank you for your enquiry. There is no information currently available about the working dilution for this antibody in IHC and Western blot. For a purified antibody, we recommend starting dilutions for Western blot to be 1 ug/mL and for IHC, 10 ug/mL. I hope this information helps, please do not hesitate to contact us if you need any more advice or information.

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