Anti-Cytokeratin 18 antibody [E431-1] (ab32118)


  • Product name
    Anti-Cytokeratin 18 antibody [E431-1]
    See all Cytokeratin 18 primary antibodies
  • Description
    Rabbit monoclonal [E431-1] to Cytokeratin 18
  • Host species
  • Specificity
    Human Cytokeratin 18 (K18) was used as immunogen after isolation from cells pre-treated with okadaic acid or pervanadate to promote Tyr hyperphosphorylation.
  • Tested applications
    Suitable for: WB, IHC-P, ICC/IF, Flow Cyt, IHC-Frmore details
    Unsuitable for: IP
  • Species reactivity
    Reacts with: Human
  • Immunogen

    Full length native protein (purified) corresponding to Human Cytokeratin 18.

  • Positive control
    • WB: A431 cell lysate. IHC: Human colon carcinoma. ICC/ IF: HT-29 cell lysate
  • 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 ab32118 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. Detects a band of approximately 48 kDa (predicted molecular weight: 48 kDa).
IHC-P Use at an assay dependent concentration.
ICC/IF 1/100 - 1/500.


Flow Cyt 1/20.

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

IHC-Fr Use at an assay dependent dilution.
  • Application notes
    Is unsuitable for IP.
  • Target

    • Function
      Involved in the uptake of thrombin-antithrombin complexes by hepatic cells (By similarity). When phosphorylated, plays a role in filament reorganization. Involved in the delivery of mutated CFTR to the plasma membrane. Together with KRT8, is involved in interleukin-6 (IL-6)-mediated barrier protection.
    • Tissue specificity
      Expressed in colon, placenta, liver and very weakly in exocervix. Increased expression observed in lymph nodes of breast carcinoma.
    • Involvement in disease
      Defects in KRT18 are a cause of cirrhosis (CIRRH) [MIM:215600].
    • Sequence similarities
      Belongs to the intermediate filament family.
    • Post-translational
      Phosphorylation at Ser-34 increases during mitosis. Hyperphosphorylated at Ser-53 in diseased cirrhosis liver. Phosphorylation increases by IL-6.
      Proteolytically cleaved by caspases during epithelial cell apoptosis. Cleavage occurs at Asp-238 by either caspase-3, caspase-6 or caspase-7.
      O-glycosylated at multiple sites; glycans consist of single N-acetylglucosamine residues.
    • Cellular localization
      Cytoplasm > perinuclear region.
    • Information by UniProt
    • Database links
    • Alternative names
      • Cell proliferation inducing gene 46 protein antibody
      • Cell proliferation inducing protein 46 antibody
      • Cell proliferation-inducing gene 46 protein antibody
      • CK 18 antibody
      • CK-18 antibody
      • CK18 antibody
      • CYK 18 antibody
      • CYK18 antibody
      • Cytokeratin 18 antibody
      • Cytokeratin endo B antibody
      • Cytokeratin-18 antibody
      • K 18 antibody
      • K18 antibody
      • K1C18_HUMAN antibody
      • KA18 antibody
      • Keratin 18 antibody
      • Keratin 18, type I antibody
      • Keratin D antibody
      • keratin, type I cytoskeletal 18 antibody
      • Keratin-18 antibody
      • Krt18 antibody
      see all


    • Anti-Cytokeratin 18 antibody [E431-1] (ab32118) at 1/10000 dilution + A431 cell lysate

      Predicted band size: 48 kDa
      Observed band size: 48 kDa

    • Immunocytochemistry/Immunofluorescence analysis of HT-29 cells labelling Cytokeratin 18 with purified ab32118 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. The cells were co-stained with ab7291, a mouse anti-tubulin antibody (1/1000) using ab150120, an Alexa Fluor® 594-conjugated goat anti-mouse IgG (1/1000) as the secondary antibody. Nuclei were counterstained with DAPI (blue).

      For negative control 1, rabbit primary antibody was used followed by anti-mouse secondary antibody (ab150120).
      For negative control 2, mouse primary antibody (ab7291) and anti-rabbit secondary antibody (ab150077) were used.

    • ab32118 showing positive staining in Gastric adenocarcinoma tissue.

    • Overlay histogram showing MCF7 cells stained with ab32118 (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 (ab32118, 1/100 dilution) for 30 min at 22ºC. The secondary antibody used was DyLight® 488 goat anti-rabbit IgG (H+L) (ab96899) at 1/500 dilution for 30 min at 22ºC. Isotype control antibody (black line) was rabbit IgG (monoclonal) (1µg/1x106 cells) used under the same conditions. Acquisition of >5,000 events was performed. This antibody gave a positive signal in MCF7 cells fixed with 4% paraformaldehyde (10 min)/permeabilized with 0.1% PBS-Tween for 20 min used under the same conditions.

    • Fluorescent immunohistochemical analysis of paraffin-embedded human normal kidney tissue using ab32118. Green-CK18 red-PI

    • ab32118 showing positive staining in Normal colon tissue.

    • ab32118 showing positive staining in Normal kidney tissue.

    • ab32118 showing positive staining in Breast carcinoma tissue.

    • ab32118 showing negative staining in Glioma tissue.

    • ab32118 showing negative staining in Normal brain tissue.


    This product has been referenced in:
    • Duchemin-Pelletier E  et al. Stem Cell-Like Properties of CK2ß-down Regulated Mammary Cells. Cancers (Basel) 9:N/A (2017). Read more (PubMed: 28858215) »
    • Bruna A  et al. A Biobank of Breast Cancer Explants with Preserved Intra-tumor Heterogeneity to Screen Anticancer Compounds. Cell 167:260-274.e22 (2016). Read more (PubMed: 27641504) »

    See all 22 Publications for this product

    Customer reviews and Q&As

    Immunocytochemistry/ Immunofluorescence
    Human Cell (HeLa)
    Yes - 0.5% TritonX100 in PBS

    Dr. Kirk Mcmanus

    Verified customer

    Submitted Jun 03 2015

    86% homology - could detect the target signal at 1:1000 in mouse kidney and spleen using 5-fold more sensitive ECL substrate than the one we usually use.

    89% homology - blank WB in mouse brain, hea...

    Read More

    Although mouse samples were not recommended based on the western blot results below with these antibodies, there is still the possibility that the negative results in mouse might be due to the limited sample types, especially for the antibodies with hi...

    Read More
    Abcam guarantees this product to work in the species/application used in this Abreview.
    Immunohistochemistry (Frozen sections)
    Blocking step
    Serum as blocking agent for 1 hour(s) and 0 minute(s) · Concentration: 5% · Temperature: RT°C
    Human Tissue sections (A549)
    Yes - 0.5 Triton X-100

    Mrs. Aleksandra Kotlyarova

    Verified customer

    Submitted Sep 26 2013

    Abcam has not validated the combination of species/application used in this Abreview.
    Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections)
    Mouse Tissue sections (Pancreas)
    Antigen retrieval step
    Heat mediated - Buffer/Enzyme Used: Citrae pH 6
    Blocking step
    BSA / FBS as blocking agent for 30 minute(s) · Concentration: 1% · Temperature: RT°C

    Mr. Raul Peña

    Verified customer

    Submitted Dec 03 2012

    Thank you very much for your answer.
    I have contacted the laboratory to gather some more information in regards to the species testing of these antibodies. I am sorry it has taken so long time. Have you already proceeded meanwhile?
    In regards...

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    Thank you for contacting us.
    I am sorry to hear this customer has been experiencing problems with 2 of our antibodies. Would it be possible to obtain more protocol information too so that we can investigate this in more detail?
    I look forward...

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    Thank you for your reply regarding ab32118.

    I am sorry that this product did not perform as stated on the datasheet and for the inconvenience this has caused. As requested, I have issued a free of charge replacement of ab668.

    To c...

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    Thank you for calling Abcam yesterday. I am sorry about the problems with ab32118. I have processed your request to receive ab668 as a free of charge replacement. Your new order number is ******. Please let me know if there is anything else I can help ...

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    Thank you for contacting Abcam. The concentration of ab32118 is approximately 0.130mg/ml and the concentration for ab32118 is 0.185 mg/ml. If there is anything else I can do, please do hesitate to ask.

    1-10 of 13 Abreviews or Q&A


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