• Product name
  • Description
    Rabbit polyclonal to Oct4
  • Host species
  • Specificity
    The antibody reacts with 45 kDa Oct4 (also designated Oct3A) and in a less extent 33 kDa Oct3B from human, mouse, and rat samples.
  • Tested applications
    Suitable for: IHC-Fr, WB, IP, ICC/IF, Flow Cyt, IHC-Pmore details
  • Species reactivity
    Reacts with: Mouse, Rat, Human, Pig, Macaque monkey
    Predicted to work with: Chimpanzee
  • Immunogen

    Synthetic peptide (the amino acid sequence is considered to be commercially sensitive).
    (Peptide available as ab52110)

  • Positive control
    • Rat kidney tissue lysate can be used as a positive control.



Our Abpromise guarantee covers the use of ab18976 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 a concentration of 20 µg/ml.
WB Use a concentration of 1 - 2 µg/ml. Predicted molecular weight: 45 kDa.Can be blocked with Oct4 peptide (ab52110).
IP Use a concentration of 20 µg/ml.
ICC/IF Use at an assay dependent concentration. PubMed: 19736565
Flow Cyt Use at an assay dependent concentration. PubMed: 17719011

ab171870 - Rabbit polyclonal IgG, is suitable for use as an isotype control with this antibody.

IHC-P 1/100. Perform enzymatic antigen retrieval before commencing with IHC staining protocol.


  • Function
    Transcription factor that binds to the octamer motif (5'-ATTTGCAT-3'). Forms a trimeric complex with SOX2 on DNA and controls the expression of a number of genes involved in embryonic development such as YES1, FGF4, UTF1 and ZFP206. Critical for early embryogenesis and for embryonic stem cell pluripotency.
  • Tissue specificity
    Expressed in developing brain. Highest levels found in specific cell layers of the cortex, the olfactory bulb, the hippocampus and the cerebellum. Low levels of expression in adult tissues.
  • Sequence similarities
    Belongs to the POU transcription factor family. Class-5 subfamily.
    Contains 1 homeobox DNA-binding domain.
    Contains 1 POU-specific domain.
  • Developmental stage
    Highly expressed in undifferentiated embryonic stem cells and expression decreases gradually after embryoid body (EB) formation.
  • Domain
    The POU-specific domain mediates interaction with PKM2.
  • Post-translational
    Sumoylation enhances the protein stability, DNA binding and transactivation activity. Sumoylation is required for enhanced YES1 expression.
    Ubiquitinated; undergoes 'Lys-63'-linked polyubiquitination by WWP2 leading to proteasomal degradation.
  • Cellular localization
    Nucleus. Expressed in a diffuse and slightly punctuate pattern.
  • Information by UniProt
  • Database links
  • Alternative names
    • Octamer binding transcription factor 4 antibody
    • MGC22487 antibody
    • Oct 3 antibody
    • Oct 4 antibody
    • Oct-3 antibody
    • Oct-4 antibody
    • OCT3 antibody
    • Oct4 antibody
    • Octamer binding protein 3 antibody
    • Octamer binding protein 4 antibody
    • Octamer binding transcription factor 3 antibody
    • Octamer-binding protein 3 antibody
    • Octamer-binding protein 4 antibody
    • Octamer-binding transcription factor 3 antibody
    • OTF 3 antibody
    • OTF 4 antibody
    • OTF-3 antibody
    • OTF3 antibody
    • OTF4 antibody
    • PO5F1_HUMAN antibody
    • POU class 5 homeobox 1 antibody
    • POU domain class 5 transcription factor 1 antibody
    • POU domain transcription factor OCT4 antibody
    • POU domain, class 5, transcription factor 1 antibody
    • POU-type homeodomain-containing DNA-binding protein antibody
    • POU5F1 antibody
    see all


  • Immunohistochemistry analysis of paraffin-embedded human breast tissues (5 µm thick) labeling Oct4 with ab18976 at 1/100 dilution.

    Tissues were rehydrated in deionized water and incubated in PBS prior to per meabilization in 0.1% PBS-TritonX 100 and overnight incubation with ab18976 in a humid chamber.Washing in PBS and secondary antibody (Alexa Fluor®) incubation for 2h was followed by a final wash and mounting.

    Blue: DAPI stain for nuclei.

    Minimal and mostly cytoplasmic expression was seen in the normal resting breast (left panel). During normal lactation (right panel), OCT4 was upregulated and expressed in both the nucleus and cytoplasm.

  • Anti-Oct4 antibody (ab18976) at 1/500 dilution + mouse embryonic stem cell whole cell lysate at 100 µg/ml

    HRP conjugated goat anti-rabbit

    Developed using the ECL technique.

    Performed under reducing conditions.

    Predicted band size: 45 kDa
    Observed band size: 45 kDa
    Additional bands at: 25 kDa (possible non-specific binding), 60 kDa (possible non-specific binding)

    Exposure time: 1 minute

    The blot was blocked with 5% milk for 1 hour at RT and inbubated with the primary antibody for 16 hours at 4°C.

    See Abreview

  • Immunohistochemical analysis of paraffin embedded Human breast tissues (5 µm thick) labeling Oct4 with ab18976 at 1/100 to 1/200 dilution. Heat induced epitope retrieval was performed at 100°C for 30 min. Slides were counterstained with hematoxylin.

    Minimal and mostly cytoplasmic expression was seen in the normal resting breast (left panel). During normal lactation (right panel), OCT4 was upregulated and expressed in both the nucleus and cytoplasm.

  • ab18976 at 1/100 dilution staining Oct-4 in mouse brain tissue by immunohistochemistry (formalin/PFA-fixed paraffin-embedded sections). Sections were paraformaldehyde fixed prior to blocking in 5% BSA for 1 hour at 25°C and then incubated with ab18976 for 12 hours at 4°C. A Cy3 conjugated donkey polyclonal to rabbit Ig, diluted 1/500, was used as the secondary antibody.

    See Abreview

  • Anti-Oct4 antibody (ab18976) at 0.5 µg/ml + Lysates prepared from rat kidney tissue.

    Predicted band size: 45 kDa

    The antibody reacts with 45 kDa Oct4 (also designated Oct-3A) and in a less extent 33 kDa Oct-3B from human, mouse, and rat samples.


This product has been referenced in:
  • Su X  et al. Embryonic lethality in mice lacking Trim59 due to impaired gastrulation development. Cell Death Dis 9:302 (2018). Read more (PubMed: 29467473) »
  • Balahmar RM  et al. Identification and characterisation of NANOG+/ OCT-4high/SOX2+ doxorubicin-resistant stem-like cells from transformed trophoblastic cell lines. Oncotarget 9:7054-7065 (2018). Read more (PubMed: 29467949) »

See all 70 Publications for this product

Customer reviews and Q&As

Thank you and your customer for taking the time to complete our questionnaire and contact us. I am sorry to hear your customer has had difficulty obtaining satisfactory results from this antibody. The details your customer has kindly provided will enab...

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Thank you for your enquiry and your interest.

I can confirm that two isoforms of Oct 4 have been identified, and the exact amino acid sequences (aa) can be found at this website: http://www.uniprot.org/uniprot/Q01860

- Isoform A: Q0...

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Muchas gracias por tu respuesta.

Es importante que todos los anticuerpos que escojas para llevar a cabo IHC-P en tejido humano estén validados (y por tanto garantizados por Abcam) para funcionar en esta especie y aplicación. Est...

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Thank you for contacting us.

Please advice customer to consult publication whole selecting the antibodies.

HEK293T cells do not express c-Myc and Oct4. They express SOX2.


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Thank you very much for your email. I apologize for this confusion. Unfortunately I do not know where it comes from. I can however confirm that the immunogen used for this antibody is from amino acid 1 to 14. The sequence is AGHLASDFAFSPC. ...

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Thank you for taking time to complete our questionnaire. I am sorry to hear that this antibody is not providing satisfactory results. The details provided will enable us to investigate this case and will provide us with vital information for monitoring...

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Tanya is still unwell and I would like to reply to you to prevent further delays. I have looked at the customer' protocol again and I think it will be very important to run a good positive control along the customer's samples. I was unable to find a...

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Thank you for your enquiry. In response to your question: ab18976 is a Rabbit IgG antiserum and therefore I would recommend ab6721, ab6795, ab6802, ab6829, ab7083, ab7090 as secondary antibodies. All of these sera have been shown to work by Dot, EL...

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Thank you for your enquiry. Yes, ab18976, anti-Oct4 has been shown to immunoprecipitate Oct4 in murine cells. Please can you tell me whether you received the IP protocol that I e-mailed yesterday? This is the best protocol I can advise for the immu...

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Thank you for your enquiry. We do not have a protocol that directly relates to this antiserum. However, we do have comprehensive protocols for all of the applications that Abcam's antisera can be applied to. I have e-mailed you in a follow up e-m...

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