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Human IL-1ra/IL-1F3 DuoSet ELISA

Bio-Techne includes R&D Systems | Catalog # DY280

Catalog #
Size / Price

Ancillary Products Available

Key Product Details

Assay Type

Solid Phase Sandwich ELISA

Assay Range

39.1-2500 pg/mL

Sample Type

Cell culture supernates, serum, and plasma
Note: Diluents for complex matrices, such as serum and plasma, should be evaluated prior to use in this DuoSet



Human IL-1ra/IL-1F3 DuoSet ELISA Features

  • Optimized capture and detection antibody pairings with recommended concentrations save lengthy development time
  • Development protocols are provided to guide further assay optimization
  • Assay can be customized to your specific needs
  • Economical alternative to complete kits

Product Summary for Human IL-1ra/IL-1F3 DuoSet ELISA

This DuoSet ELISA Development kit contains the basic components required for the development of sandwich ELISAs to measure natural and recombinant human IL-1ra/IL-1F3. The suggested diluent is suitable for the analysis of most cell culture supernate samples. Diluents for complex matrices, such as serum and plasma, should be evaluated prior to use in this DuoSet.


Product Specifications

Assay Format

96-well strip plate (sold separately)

Sample Volume Required

100 µL

Detection Method

Colorimetric ELISA - 450nm (TMB)





Scientific Data Images for Human IL-1ra/IL-1F3 DuoSet ELISA

Human IL-1ra / IL-1F3 ELISA Standard Curve

Human IL-1ra / IL-1F3 ELISA Standard Curve

Kit Contents for Human IL-1ra/IL-1F3 DuoSet ELISA

  • Capture Antibody
  • Detection Antibody
  • Recombinant Standard
  • Streptavidin conjugated to horseradish-peroxidase (Streptavidin-HRP)

Other Reagents Required

DuoSet Ancillary Reagent Kit 2 (5 plates): (Catalog # DY008) containing 96 well microplates, plate sealers, substrate solution, stop solution, plate coating buffer (PBS), wash buffer, and Reagent Diluent Concentrate 2.

The components listed above may be purchased separately:

PBS: (Catalog # DY006), or 137 mM NaCl, 2.7 mM KCl, 8.1 mM Na2HPO4, 1.5 mM KH2PO4, pH 7.2 - 7.4, 0.2 µm filtered

Wash Buffer: (Catalog # WA126), or 0.05% Tween® 20 in PBS, pH 7.2-7.4

Reagent Diluent: (Catalog # DY995), or 1% BSA in PBS, pH 7.2-7.4, 0.2 µm filtered

Substrate Solution: 1:1 mixture of Color Reagent A (H2O2) and Color Reagent B (Tetramethylbenzidine) (Catalog # DY999)

Stop Solution: 2 N H2SO4 (Catalog # DY994)

Microplates: R&D Systems (Catalog # DY990)

Plate Sealers: ELISA Plate Sealers (Catalog # DY992)

Preparation and Storage


The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.

Stability & Storage

Store the unopened product at 2 - 8 °C. Do not use past expiration date.

Background: IL-1ra/IL-1F3

Interleukin-1 receptor antagonist (IL-1ra; also known as IL-1F3) is a 22-25 kDa member of the IL-1 family of cytokines. Currently, there are 11 family members (IL-1F1-F11), nine of which form an IL-1 gene cluster on human Ch2 (1-3). Each IL-1 family member contains an IL-1 fold. This fold is generated by 12 packed beta-sheets that interact to form a beta-trefoil structure. Little amino acid (aa) homology is required to achieve this structure, and this explains the low aa identity among IL-1 family members. IL-1ra is a pure cytokine receptor antagonist that has no signal transduction-initiating activity (4). It is an acute phase protein that exists to dampen inflammation. IL-1( beta) is initially produced by monocytes in response to a variety of stimuli. Circulating IL-1 then binds to widely expressed IL-1 type I receptors (IL-1 RI) and initiates a number of pro-inflammatory events. On endothelial cells (EC), IL-1 induces PGE2 and IL-6 release, generating fever, thrombocytosis, and hepatic acute phase protein production. In synovial joints, IL-1 induces chondrocyte NO production, an event that leads to reduced collagen synthesis and chondrocyte apoptosis. Finally, IL-1 increases neutrophil counts, both in blood and tissue, and thus is able to promote a pro-inflammatory environment in multiple locations (5-8). IL-1ra blocks IL-1 action through competitive inhibition. More correctly, although IL-1ra fills the IL-1 binding site in IL-1 RI, it is also unable to orchestrate the creation of a signal-transducing IL-1 RI:IL-1 R Accessory protein (IL-1 R AcP) heterodimer complex. Effective IL-1ra concentrations are generally 100-fold greater than local IL-1 concentrations. This is because the IL-1ra half-life is but 6 minutes, and very few IL-1 type I receptors need to be engaged by IL-1 to elicit a cellular response (5, 7, 9). 
Human IL-1ra is synthesized as a 177 aa precursor that contains a 25 aa signal sequence and a 152 aa mature region (10, 11). Although it contains an IL-1 cytokine fold, it apparently lacks two structural motifs that allow for activation of the IL-1 receptor heterodimer. First, and following binding to IL-1 RI, the presence of Ile 51-His 54 and Lys 145 of the mature molecule preclude recruitment of IL-1 R AcP. Second, there is no identifiable C-terminal lectin segment that is hypothesized to help recruit an accessory signaling component (1, 12, 13). Mature human IL-1ra is 77% and 82% aa identical to mouse and canine IL-1ra, respectively, and human IL-1ra inhibits IL-1 activity on mouse cells (10). A number of cell types express IL-1ra, including monocytes (11), Sertoli cells (14), hepatocytes (15), adipocytes (16), synovial fibroblasts (17), mast cells (18), pancreatic beta-cells (19), and intestinal epithelial cells (20). There are at least three intracellular IL-1ra isoforms (icIL-1ra1, 2, and 3). All show N-terminal variation, and all contain amino acids 35-177 of the secreted precursor (21-23). Intracellular IL-1ra1 is of particular interest, because it is reported to be "secreted" by endothelial cells and binds to the IL-1 RI in an antagonist fashion (23-25). Intracellular IL-1ra1 is 159 aa in length and shows a 3 aa substitution for the first 21 aa's of the signal sequence of IL-1ra (21).

Long Name

Interleukin 1 Receptor Antagonist

Alternate Names

DIRA, ICIL-1ra, IL-1F3, IL-1ra3, IL-1RN, IL1ra, IL1RN, MVCD4

Entrez Gene IDs

3557 (Human); 16181 (Mouse); 60582 (Rat); 397499 (Porcine)

Gene Symbol


Additional IL-1ra/IL-1F3 Products

Product Documents for Human IL-1ra/IL-1F3 DuoSet ELISA

Certificate of Analysis

To download a Certificate of Analysis, please enter a lot number in the search box below.

Note: Certificate of Analysis not available for kit components.

Product Specific Notices for Human IL-1ra/IL-1F3 DuoSet ELISA

For research use only

Citations for Human IL-1ra/IL-1F3 DuoSet ELISA (29)

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Customer Reviews for Human IL-1ra/IL-1F3 DuoSet ELISA (3)

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  • Human IL-1ra/IL-1F3 DuoSet ELISA
    Name: Leslie Priddy
    Sample Tested: Serum
    Verified Customer | Posted 04/01/2018
  • Human IL-1ra/IL-1F3 DuoSet ELISA
    Name: Balaji Mahender
    Sample Tested: EDTA Plasma
    Verified Customer | Posted 03/19/2018
  • Human IL-1ra/IL-1F3 DuoSet ELISA
    Name: BOCHATON Thomas
    Sample Tested: Serum
    Verified Customer | Posted 08/29/2017
    Very good ELISA. We used human serum with no dilution. In our conditions, IL-1ra was not detectable in human seum.
    Human IL-1ra/IL-1F3 DuoSet ELISA DY280

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