• Product nameAnti-IRF3 antibody [IRF35I218]
    See all IRF3 primary antibodies
  • Description
    Mouse monoclonal [IRF35I218] to IRF3
  • Tested applicationsSuitable for: ICC/IF, WB, Flow Cytmore details
  • Species reactivity
    Reacts with: Human
  • Immunogen


  • Positive control
    • HEK293 whole cell lysate RIPA lysate of HeLa cells Hela cells



Our Abpromise guarantee covers the use of ab50772 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
ICC/IF 1/10.
WB 1/50 - 1/100. Detects a band of approximately 55 kDa (predicted molecular weight: 47 kDa).
Flow Cyt Use 1µg for 106 cells. ab170190-Mouse monoclonal IgG1, is suitable for use as an isotype control with this antibody.


  • FunctionMediates interferon-stimulated response element (ISRE) promoter activation. Functions as a molecular switch for antiviral activity. DsRNA generated during the course of an viral infection leads to IRF3 phosphorylation on the C-terminal serine/threonine cluster. This induces a conformational change, leading to its dimerization, nuclear localization and association with CREB binding protein (CREBBP) to form dsRNA-activated factor 1 (DRAF1), a complex which activates the transcription of genes under the control of ISRE. The complex binds to the IE and PRDIII regions on the IFN-alpha and IFN-beta promoters respectively. IRF-3 does not have any transcription activation domains.
  • Tissue specificityExpressed constitutively in a variety of tissues.
  • Sequence similaritiesBelongs to the IRF family.
    Contains 1 IRF tryptophan pentad repeat DNA-binding domain.
  • Post-translational
    Constitutively phosphorylated on many serines residues. C-terminal serine/threonine cluster is phosphorylated in response of induction by IKBKE and TBK1. Ser-385 and Ser-386 may be specifically phosphorylated in response to induction. An alternate model propose that the five serine/threonine residues between 396 and 405 are phosphorylated in response to a viral infection. Phosphorylation, and subsequent activation of IRF3 is inhibited by vaccinia virus protein E3.
    Ubiquitinated; ubiquitination involves RBCK1 leading to proteasomal degradation. Polyubiquitinated; ubiquitination involves TRIM21 leading to proteasomal degradation.
    ISGylated by HERC5 resulting in sustained IRF3 activation and in the inhibition of IRF3 ubiquitination by disrupting PIN1 binding. The phosphorylation state of IRF3 does not alter ISGylation.
  • Cellular localizationCytoplasm. Nucleus. Shuttles between cytoplasmic and nuclear compartments, with export being the prevailing effect. When activated, IRF3 interaction with CREBBP prevents its export to the cytoplasm.
  • Information by UniProt
  • Database links
  • Alternative names
    • Interferon regulatory factor 3 antibody
    • IRF 3 antibody
    • IRF-3 antibody
    • IRF3 antibody
    • IRF3_HUMAN antibody
    • MGC94729 antibody
    see all

Anti-IRF3 antibody [IRF35I218] images

  • Overlay histogram showing HeLa cells stained with ab50772 (red line). The cells were fixed with 80% methanol (5 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 (ab50772, 1μg/1x106 cells) for 30 min at 22°C. The secondary antibody used was Alexa Fluor® 488 goat anti-mouse IgG (H&L) (ab150113) at 1/2000 dilution for 30 min at 22°C. Isotype control antibody (black line) was mouse IgG1 [ICIGG1] (ab91353, 1μg/1x106 cells) used under the same conditions. Unlabelled sample (blue line) was also used as a control. Acquisition of >5,000 events were collected using a 20mW Argon ion laser (488nm) and 525/30 bandpass filter.
  • Immunofluorescent staining of HeLa cells with a 1/10 dilution of ab50772 as primary antibody and AlexaFluor®488 conjugated Goat Anti-mouse IgG diluted 1/200 as the secondary antibody
  • Anti-IRF3 antibody [IRF35I218] (ab50772) at 1/50 dilution + HT-1080 whole cell lysate at 25 µg

    Anti mouse IgG at 1/2500 dilution

    Predicted band size : 47 kDa
    Observed band size : 55 kDa (why is the actual band size different from the predicted?)
  • Anti-IRF3 antibody [IRF35I218] (ab50772) at 1/100 dilution + Ripa lysate of Hela cells at 500 µg

    Anti-mouse IgG at 1/1000 dilution

    Predicted band size : 47 kDa
    Observed band size : 55 kDa (why is the actual band size different from the predicted?)
    IRF3 antibody [IRF35I218] (ab50772) at 1/100 dilution + Ripa lysate of Hela cells at 500 µg Secondary Anti-mouse IgG at 1/1000 dilution

References for Anti-IRF3 antibody [IRF35I218] (ab50772)

This product has been referenced in:
  • Brownell J  et al. Direct, interferon-independent activation of the CXCL10 promoter by NF-?B and interferon regulatory factor 3 during hepatitis C virus infection. J Virol 88:1582-90 (2014). Read more (PubMed: 24257594) »
  • Wang J  et al. Morphine inhibits murine dendritic cell interleukin 23 production by modulating TLR2 and Nod2 signaling. J Biol Chem : (2011). ICC/IF ; Mouse . Read more (PubMed: 21245149) »

See all 4 Publications for this product

Product Wall

Unfortunately, when we test our IRF-3 antibodies we do not specifically test them in activating conditions so we have no results to share with you. However, several of our antibodies have been used in publications under such conditions and so I believe...

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Merci de nous avoir contactés.

Nous sommes désolés que le produit que vous avez reçu ne fonctionne pas comme attendu.

Comme convenu j'ai mis en place l'envoi d'une unité de ab50772 en remplacement ...

Read More

Apologies for the attachment not coming through in the last email. I have attached file again.

Please let me know if there is anything else I can help you with.

Thank you for contacting Abcam.

The protocol used to generate the IF image that we talked about on the datasheet for ab50772 is attached, there was no activation step performed before the staining:

Abcam guarantees this product to work in the species/application used in this Abreview.
Application Western blot
Sample Human Cell lysate - whole cell (HEK293T and hela)
Loading amount 25 µg
Specification HEK293T and hela
Gel Running Conditions Reduced Denaturing
Blocking step Milk as blocking agent for 1 hour(s) and 0 minute(s) · Concentration: 5% · Temperature: 25°C

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Submitted Nov 15 2007