• Product name
  • Description
    Goat polyclonal to TFPI
  • Host species
  • Tested applications
    Suitable for: WB, Electron Microscopymore details
  • Species reactivity
    Reacts with: Human
    Predicted to work with: Rhesus monkey
  • Immunogen

    Synthetic peptide: VKIAYEEIFVKNM, corresponding to C terminal amino acids 292-304 of Human TFPI.

  • Positive control
    • HeLa lysate
  • General notes
    Principal Names - TFPI: tissue factor pathway inhibitor; Lipoprotein-associated coagulation inhibitor; LACI Official Gene Symbol - TFPI GenBank Accession Number – NP_006278 LocusLink ID - 7035

    A protease inhibitor that inhibits fibrin clot formation.


  • Form
  • Storage instructions
    Shipped at 4°C. Upon delivery aliquot and store at -20°C or -80°C. Avoid repeated freeze / thaw cycles.
  • Storage buffer
    Preservative: 0.02% Sodium Azide
    Constituents: 0.5% BSA, Tris buffered saline, pH 7.3
  • Concentration information loading...
  • Purity
    Immunogen affinity purified
  • Purification notes
    Purified from goat serum by ammonium sulphate precipitation followed by antigen affinity chromatography using the immunizing peptide.
  • Primary antibody notes
    A protease inhibitor that inhibits fibrin clot formation.
  • Clonality
  • Isotype
  • Research areas


Our Abpromise guarantee covers the use of ab9881 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 Use a concentration of 0.3 - 1 µg/ml. Can be blocked with Human TFPI peptide (ab23168).
Electron Microscopy Use at an assay dependent dilution. PubMed: 20592020


  • Function
    Inhibits factor X (X(a)) directly and, in a Xa-dependent way, inhibits VIIa/tissue factor activity, presumably by forming a quaternary Xa/LACI/VIIa/TF complex. It possesses an antithrombotic action and also the ability to associate with lipoproteins in plasma.
  • Tissue specificity
    Mostly in endothelial cells.
  • Sequence similarities
    Contains 3 BPTI/Kunitz inhibitor domains.
  • Domain
    This inhibitor contains three inhibitory domains. The first domain interacts with VIIa and TF, the second one with Xa.
  • Post-translational
  • Cellular localization
  • Information by UniProt
  • Database links
  • Alternative names
    • Anti convertin antibody
    • EPI antibody
    • Extrinsic pathway inhibitor antibody
    • LACI antibody
    • Lipoprotein associated coagulation inhibitor antibody
    • Lipoprotein-associated coagulation inhibitor antibody
    • TFI antibody
    • TFPI 1 antibody
    • TFPI antibody
    • TFPI1 antibody
    • TFPI1_HUMAN antibody
    • Tissue factor pathway inhibitor (lipoprotein associated coagulation inhibitor) antibody
    • Tissue factor pathway inhibitor antibody
    see all


This product has been referenced in:
  • Tinholt M  et al. Syndecan-3 and TFPI colocalize on the surface of endothelial-, smooth muscle-, and cancer cells. PLoS One 10:e0117404 (2015). Read more (PubMed: 25617766) »
  • Papareddy P  et al. C-terminal Peptides of Tissue Factor Pathway Inhibitor Are Novel Host Defense Molecules. J Biol Chem 285:28387-98 (2010). Electron Microscopy . Read more (PubMed: 20592020) »
See all 2 Publications for this product

Customer reviews and Q&As

1-6 of 6 Abreviews or Q&A


Thank you for your reply.
Thank you for trying some of the tips. Please do let me know what the results are once you have them. I'm curious myself, as well as want to ensure the antibodies are working as expected.

Should it turn out that one or bothantibodies are not working as expected, and they were purchased within the last 6 months, we can discuss then other options of resolving the issue.

I wish you good luck and look forward to hear back from you.

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Thank you for your reply and the additional information.

I have a couple more questions as well as a few suggestions. I hope you don't mind.

1) Is the rTFPI that you were showing on the left hand side glycosylated or not?
2) Both antibodies show a strong band and lots of weaker bands, whereas ab66544 is cleaner than ab9881.
3) According to your description of using PI-PLC, it seems that only ab66544 gives you the expected decrease in signal.

Other ways to check if the correct bands are detected is (1) to de-glycosylate the sample and repeat the WB. The MW of the band should shift to 35 kDa for alpha and 29 kDa for beta isoform.

(2) Further using a positive control (e.g. HeLa lysate (ab29545) [https://www.abcam.com/HeLa-Human-epithelial-carcinoma-cell-line-Whole-Cell-Lysate-ab29545.html] or Jurkat cell lysate (ab7899)[https://www.abcam.com/Jurkat-Human-T-cell-lymphoblast-like-cell-line-Whole-Cell-Lysate-ab7899.html]) could be of help to compare your results with the expected results for the antibodies.

(3) Using less primary and maybe also less secondary antibody could help to reduce the background bands, but would not solve the issue of differing band sizes.

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.

Antibody ab9881, detects only the alpha isoform.
Antibody ab66544, would detect both isoforms if they are present
For antibody ab48648, we do not know where the epitope is, thus we cannot predict if either one or both isoforms can be detected. I can check with the lab where they saw a band in WB, though.

Unglycosylated TFPI has a MW of35 kDa for the alpha isoform, and29 kDafor the beta isoform.
The glycoslyation would shift the MW to a higher kDa value.
Glycosylation patterncan also vary based on tissue / species / treatment used.

I'd like to ask you a few more questions to understand your experiment better:
1) What samples are you using?
2) What antibody dilutions are you using?
3) Could you please an image of the WB with both antibodies?
4) For ab66544, do you also see bands at 45-46 kDa?

Assuming that your samples contain both isoforms, then the only explanation for the results you see is that the glycosylation of isoform beta is heavier than for alpha isoform.
If only one isoform is present then this seems to be isoform alpha. For ab66544, we also saw the band at 52 kDa and your results would match our findings.

I'll check with the lab regarding ab48648.

I look forward to hear back from you and assist you further.

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Thank you for your enquiry. You can use reducing Western blotting conditions (if non-reducing conditions are required, we would state this information on the online datasheet). We would recommend blocking with either 5% w/v nonfat dry milk or 5% w/v BSA in PBST or TBST. If you have any additional questions, please contact us again.

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Thank you for your enquiry. To our knowledge, this antibody has yet to be tested in FACS. All tested applications are specified on Abcam product datasheets. If you decide to go ahead and purchase this product, please let us know how you get on and in return we will forward a reward of your choice, typically an Amazon gift voucher.

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This is a new antibody that has only yet been tested on human.

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