• Product name
    Human Factor XI ELISA Kit (with plasma controls)
    See all Factor XI kits
  • Detection method
  • Precision
    Sample n Mean SD CV%
    Overall 5%
    Sample n Mean SD CV%
    Overall 8.7%
  • Sample type
    Cell culture supernatant, Serum, Plasma, Cell Lysate
  • Assay type
    Sandwich (quantitative)
  • Sensitivity
    > 1.3 ng/ml
  • Range
    1.562 ng/ml - 50 ng/ml
  • Recovery

    = 95 %

    Sample specific recovery
    Sample type Average % Range
    Serum 93% - 101%
    Plasma 91% - 103%

  • Assay time
    4h 00m
  • Assay duration
    Multiple steps standard assay
  • Species reactivity
    Reacts with: Human
  • Product overview

    Abcam’s Factor XI Human in vitro ELISA (Enzyme-Linked Immunosorbent Assay) kit is designed for the quantitative measurement of Factor XI concentrations in cell culture supernatants, serum and plasma.

    A Factor XI specific antibody has been precoated onto 96-well plates and blocked. Standards or test samples are added to the wells and subsequently a Factor XI specific biotinylated detection antibody is added and then followed by washing with wash buffer. Streptavidin-Peroxidase Conjugate is added and unbound conjugates are washed away with wash buffer. TMB is then used to visualize Streptavidin-Peroxidase enzymatic reaction. TMB is catalyzed by Streptavidin-Peroxidase to produce a blue color product that changes into yellow after adding acidic stop solution. The density of yellow coloration is directly proportional to the amount of Factor XI captured in plate.

  • Tested applications
    Suitable for: Sandwich ELISAmore details


  • Storage instructions
    Store at -20°C. Please refer to protocols.
  • Components 1 x 96 tests
    100X Streptavidin-Peroxidase Conjugate 1 x 80µl
    10X Diluent M Concentrate 1 x 30ml
    20X Wash Buffer Concentrate 2 x 30ml
    50X Biotinylated Human Factor XI Antibody 1 x 120µl
    Chromogen Substrate 1 x 8ml
    Factor XI Microplate (12 x 8 well strips) 1 unit
    Factor XI Standard 1 vial
    Negative control (Depleted Human Plasma) 1 vial
    Positive control (Reference Plasma Control) 1 vial
    Sealing Tapes 3 units
    Stop Solution 1 x 12ml
  • Research areas
  • Function
    Factor XI triggers the middle phase of the intrinsic pathway of blood coagulation by activating factor IX.
  • Tissue specificity
    Isoform 2 is produced by platelets and megakaryocytes but absent from other blood cells.
  • Involvement in disease
    Factor XI deficiency (FA11D) [MIM:612416]: A hemorrhagic disease characterized by reduced levels and activity of factor XI resulting in moderate bleeding symptoms, usually occurring after trauma or surgery. Patients usually do not present spontaneous bleeding but women can present with menorrhagia. Hemorrhages are usually moderate. Note=The disease is caused by mutations affecting the gene represented in this entry.
  • Sequence similarities
    Belongs to the peptidase S1 family. Plasma kallikrein subfamily.
    Contains 4 apple domains.
    Contains 1 peptidase S1 domain.
  • Post-translational
    Activated by factor XIIa (or XII), which cleaves each polypeptide after Arg-387 into the light chain, which contains the active site, and the heavy chain, which associates with high molecular weight (HMW) kininogen.
  • Cellular localization
  • Information by UniProt
  • Alternative names
    • Coagulation factor XI
    • Coagulation factor XIa light chain
    • F11
    • FA11_HUMAN
    • FXI
    • Plasma thromboplastin antecedent
    • PTA
    see all
  • Database links

Associated products


Our Abpromise guarantee covers the use of ab168547 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
Sandwich ELISA Use at an assay dependent concentration.


  • Representative Standard Curve using ab168547



ab168547 has not yet been referenced specifically in any publications.

Customer reviews and Q&As

Testing cross reactivity in Rhesus EDTA plasma

Good Excellent 5/5 (Ease of Use)
The Factor XI ELISA, using the Abcam human ELISA kit, was performed by an experienced laboratory technician at an accredited university. The goal of the experiment was to analyze the linearity of dilutions of rhesus macaque EDTA-prepared plasma samples, but more specifically, to analyze the cross-reactivity for rhesus macaque.

Overall, the kit, like other Abcam ELISA kits, was easy to follow, clear in terms of directions, and brief yet thorough. The laboratory technician had no problems understanding any of the protocol’s steps.

Our experiment consisted of using EDTA-prepared Rhesus Macaque plasma samples from N=3 M. mulatta. Samples were stored prior to thaw at -80 degrees Celsius. Plasma was diluted 1:300, 1:600, 1:1200, and 1:2400 in the given diluent as duplicates. The rest of the assay was performed per protocol’s instructions.

Absorbance values for the controls were lower compared to this technician’s experience with other ELISA assays.

Absorbance measurements of the diluted samples were very comparable between duplicates however, there was a lack of linearity between all dilutions. This was not only seen in these first four dilutions, but also as the laboratory technician repeated the experiment with lower dilutions (including 1:25, 1:50, 1:100, 1:200 and 1:400). Several values were out of the range of standards (included as gaps in image), but all had similar duplicate values.

Negative and positive controls were used as provided by the kit. We find this a valuable addition to any commercial ELISA. Positive control was accurate both experiments achieved the target value between 7-28 ng/mL, suggesting plating/storage was proper. Negative control seemed to work properly as well producing values near the “blank” standard.

The standard curve was accurate for the first run between duplicate wells however, for the second run of the experiment, the standard curve was found to be difficult to reproduce accurately between duplicates, suggesting several cold/hot cycles may damage the standards.

The technician also performed a spike recovery, and found data suggesting that, between pure diluent with known standard and plasma with known standard, plasma masked the known standard’s concentration in detection using this assay. A spiked concentration of 25ng/ml into plasma samples diluted at 1:300 produced a value measured at 7ng/mL, suggesting that there may be something in the plasma preventing accurate measurement of this protein.

Overall, we do not recommend this kit for detection of Factor XI in EDTA-prepared Rhesus macaque plasma samples.

Abcam user community

Verified customer

Submitted Jun 01 2016


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