• Product name

    Human C1 inhibitor ELISA Kit
    See all C1 inhibitor kits
  • Detection method

  • Precision

    Sample n Mean SD CV%
    Serum 9 1.9%
    Sample n Mean SD CV%
    Serum 3 9.4%
  • Sample type

    Cell culture supernatant, Serum, Heparin Plasma, EDTA Plasma, Citrate Plasma
  • Assay type

    Sandwich (quantitative)
  • Sensitivity

    10.9 pg/ml
  • Range

    31.25 pg/ml - 2000 pg/ml
  • Recovery

    Sample specific recovery
    Sample type Average % Range
    Cell culture supernatant 92 89% - 95%
    Serum 113 111% - 114%
    Heparin Plasma 100 92% - 108%
    EDTA Plasma 102 91% - 107%
    Citrate Plasma 106 101% - 112%

  • Assay time

    1h 30m
  • Assay duration

    One step assay
  • Species reactivity

    Reacts with: Human
    Does not react with: Mouse, Rat, Cow
  • Product overview

    C1 inhibitor in vitro SimpleStep ELISA® (Enzyme-Linked Immunosorbent Assay) kit is designed for the quantitative measurement of C1 inhibitor protein in Human  serum, plasma, and cell culture supernatants.

    The SimpleStep ELISA® employs an affinity tag labeled capture antibody and a reporter conjugated detector antibody which immunocapture the sample analyte in solution. This entire complex (capture antibody/analyte/detector antibody) is in turn immobilized via immunoaffinity of an anti-tag antibody coating the well. To perform the assay, samples or standards are added to the wells, followed by the antibody mix. After incubation, the wells are washed to remove unbound material. TMB substrate is added and during incubation is catalyzed by HRP, generating blue coloration. This reaction is then stopped by addition of Stop Solution completing any color change from blue to yellow. Signal is generated proportionally to the amount of bound analyte and the intensity is measured at 450 nm. Optionally, instead of the endpoint reading, development of TMB can be recorded kinetically at 600 nm.

    C1 inhibitor, also known as C1 esterase inhibitor and Serpin G1, is a protease inhibitor belonging to the serpin superfamily, and is encoded by the gene SERPING1. C1 inhibitor is a 478 -amino acid containing protein, and is heavily glycosylated with an approximate 105 kDa molecular mass. The primary function of C1 inhibitor is the inhibition of the classical complement cascade to suppress spontaneous activation by forming an inactive complex with C1r and C1s proteases. In addition, C1 inhibitor also inactivates proteases of the fibrinolytic, clotting, and kinin pathways. The levels of C1 inhibitor in blood fluctuate during inflammation, and deficiencies of C1 inhibitor are associated with hereditary angioedema.        

  • Tested applications

    Suitable for: Sandwich ELISAmore details
  • Platform

    Pre-coated microplate (12 x 8 well strips)


  • Storage instructions

    Store at +4°C. Please refer to protocols.
  • Components 1 x 96 tests
    10X Wash Buffer PT (ab206977) 1 x 20ml
    50X Cell Extraction Enhancer Solution (ab193971) 1 x 1ml
    5X Cell Extraction Buffer PTR (ab193970) 1 x 10ml
    Antibody Diluent 4BI 1 x 6ml
    10X Human C1 inhibitor Capture Antibody 1 x 600µl
    10X Human C1 inhibitor Detector Antibody 1 x 600µl
    Human C1 inhibitor Lyophilized Recombinant Protein 2 vials
    Plate Seals 1 unit
    Sample Diluent NS 1 x 50ml
    SimpleStep Pre-Coated 96-Well Microplate (ab206978) 1 unit
    Stop Solution 1 x 12ml
    TMB Development Solution 1 x 12ml
  • Research areas

  • Relevance

    C1 inhibitor functions as a regulator of the activation of the classical complement pathway and of the contact activation system of kinin generation and coagulation. Its primary biologically relevant target proteinases are C1r, C1s, coagulation factors XIa and XIIa, and plasma kallikrein. C1-inhibitor consists of one polypeptide chain and has a molecular mass of 104 kDa. Serum concentration has been determined to 180 µg/ml.
  • Cellular localization

  • Alternative names

    • C1 INH
    • C1IN
    • C1NH
    • esterase inhibitor
    • SERPING1
    see all
  • Database links


Our Abpromise guarantee covers the use of ab224883 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.


  • SimpleStep ELISA technology allows the formation of the antibody-antigen complex in one single step, reducing assay time to 90 minutes. Add samples or standards and antibody mix to wells all at once, incubate, wash, and add your final substrate. See protocol for a detailed step-by-step guide.


  • Background-subtracted data values (mean +/- SD) are graphed.

  • The concentrations of C1 inhibitor were measured in duplicates, interpolated from the C1 inhibitor standard curves and corrected for sample dilution. Undiluted samples are as follows: serum 1:4000, plasma (citrate) 1:4000, plasma (EDTA) 1: 4,000, and plasma (heparin) 1:8000. The interpolated dilution factor corrected values are plotted (mean +/- SD, n=2). The mean C1 inhibitor concentration was determined to be 9,502 ng/mL in serum, 8,496 ng/mL in plasma (citrate), 4,285 ng/mL in plasma (EDTA), and 26,756 ng/mL in plasma (heparin).

  • HepG2 cells were cultured for 5 days in DMEM media containing 10% FBS and 1% NEAA. The concentrations of C1 inhibitor were measured in duplicate and interpolated from the C1 inhibitor standard curve and corrected for sample dilution. Undiluted samples are 18.75%. The interpolated dilution factor corrected values are plotted (mean +/- SD, n=2). The mean C1 inhibitor concentration was determined to be 1,303 pg/mL.

  • Interpolated dilution factor corrected values are plotted (mean +/- SD, n=2). The mean C1 inhibitor concentration was determined to be 12,259 pg/mL with a range of 39.7-20,572 pg/mL.



ab224883 has not yet been referenced specifically in any publications.

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