Human Resistin ELISA Kit

Sample

Serum and plasma

Species Reactivity

Human

Detection Method

sELISA

Intended Use

The Human Resistin ELISA Kit is intended to be used for quantitative measurement of human Resistin in human serum or plasma for research purposes.
Due to high sensitivity (12 pg/mL), this assay is also suitable for measurements in cell culture supernatants and in non-serum / plasma samples (e.g. in breast milk, urine, saliva).

Contents of Kit

1. Microtiter plate: ready for use, coated with rabbit-anti-resistin-antibody. Wells are separately breakable. (8x12) wells
2. Calibrators (CAL A-E): lyophilized, (recombinant human Resistin), concentrations are given on vial labels and on quality certificate. Reconstitute in 750 μL Sample Buffer SB. 5 x 750 μL
3. Control 1 (CTR1): lyophilized, (human serum), concentration is given on quality certificate. Reconstitute in 250 μL Dilution Buffer DIL. Dilute with Sample Buffer SB. 1 x 250 μL
4. Control 2 (CTR2): lyophilized, (human serum), concentration is given on quality certificate. Reconstitute in 250 μL Dilution Buffer DIL. Dilute with Sample Buffer SB. 1 x 250 μL
5. Antibody Conjugate (DET): 100-fold concentrated, contains rabbit biotinylated anti-resistin antibody. Before use, dilute 1:100 with Dilution Buffer DIL. 1 x 120 μL
6. Enzyme Conjugate (EC): 100-fold concentrated, contains HRP (Horseradish-Peroxidase)-labelled Streptavidin. Before use, dilute 1:100 with Dilution Buffer DIL. 1 x 120 μL
7. Sample Buffer (SB): ready for use. Please shake before use! 1 x 120 mL
8. Dilution Buffer (DIL): ready for use. Please shake before use! 1 x 25 mL
9. Washing Buffer (WB): 20-fold concentrated solution. Dilute 1:20 with Aqua dest. 1 x 50 mL
10. Substrate (S): ready for use, horseradish-peroxidase-(HRP) substrate, stabilised Tetramethylbencidine. 1 x 12 mL
11. Stopping Solution (STP): ready for use, 0.2 M sulfuric acid. 1 x 12 mL
12. Sealing Tape: for covering the microtiter plate. 3

Storage

Store the kit at 2-8°C after receipt until its expiry date. The lyophilized reagents should be stored at –20 °C after reconstitution. Avoid repeated thawing and freezing.
The shelf life of the components after initial opening is warranted for 4 weeks, store the unused strips and microtiter wells airtight together with the desiccant at 2-8°C in the clip-lock bag, use in the frame provided. The reconstituted components Calibrators A-E and Controls CTR1 and CTR2 must be stored at –20°C (max. 4 weeks). For further use, thaw quickly but gently (avoid temperature increase above room temperature and avoid excessive vortexing). The 1:20 diluted Washing Buffer WB is 4 weeks stable at 2-8°C

Precision

The inter- and intra assay coefficients of variability are in average < 10%.
Inter-Assay-Variation

Intra-Assay-Variation

Sensitivity

The analytical sensitivity was determined by measuring the blank value. For this purpose, the signal intensity of blank value + 2SD was converted into a resistin concentration using the calibration curve. The analytical sensitivity of the assay is 0.012 ng / mL.

General Description

Resistin, a cysteine-rich protein of 11.3 kDa, was firstly found in mice and constitutes together with RELMα, RELMβ and RELMγ the protein family of resistin-like molecules (RELM).
In humans, resistin and RELMβ but no other proteins of the RELM family were found. The human form of resistin shows a homology of 53% to the murine protein. It has 11 cysteine-residues, is synthesized as a propetide of 108 amino acids and secreted as a dimer, build by a disulfide bridge of cysteine residues. Beside this intermolecular disulfide bridge, 5 additional intramolecular ones exist.
Appearance of multi- and oligomer formation was proved by size exclusion chromatography. Thereby it was shown, that oligomer formation is SDS-insensitive but can be inhibited by β-mercaptoethanol and is therefore likely to be caused by disulfide bridges. Further on, the resistin structure seems to be dependent on its concentration, as circular dichroism analysis shows a concentration dependent shift of α-helical to β-sheet structure.
Resistin expression was demonstrated in white adipose tissue, pituitary and pancreatic islets of mice as well as in brown adipose tissue of rats. In humans, resistin expression in adipocytes can be detected but only at a very low level. But in vitro, resistin expression of non-adipocytes in fatty tissue was shown. Human resistin gene is also expressed in pancreatic islets, pre-adipocytes, marcophages and bone marrow. So, resistin is of relevance for inflammation processes as well as for lipid metabolism.
Most investigation refers to the mouse model. Here, the existence of trimeric and hexameric resistin in serum was demonstrated. In comparison to adiponectin biology, it is highly probable that different resistin oligomers have different biologic function.
In mice, a correlation between adiposity, insulin resistance and resistin expression was found empirically. In humans, respective study results are not clear – several studies show an association of resistin serum concentration and adiposity or insulin resistance. But others failed in confirming these results. Therefore, there is requirement for valid and reproducible determination of resistin serum concentration.
Relevance of resistin in other physiologic processes than energy metabolism was investigated by several different approaches. Experiments with endothelial cells gave interesting results. Here, resistin was shown to enhance expression of VCAM-1 and ICAM-1. By this way, resistin is potentially able to influence endothelial inflammation and, thereby atherosclerosis. These results were confirmed by experiments in mice, where endothelin-1 was shown to regulate resistin secretion.
In recent research human resistin was shown to increase pre-adipocyte proliferation and lipolysis of mature adipocytes. By the way of modulating MAPK-signalling pathways resistin exerts crucial influence on energy metabolism.
Present research demonstrates, that Resistin exerts influence on a broad variety of physiological processes, however a clear and defined biological role of resistin remains still unexisting.
This ELISA-kit enables the user to determine the exact concentration of Resistin in human serum/plasma as well as other body fluids and thereby assists investigation of Resistin biology. With optimized special sample buffer: reliable quantification of resistin - independent of the absolute content.

Standard Curve

The exemplary shown calibration curve in Figure below cannot be used for calculation of your test results. You have to establish a calibration curve for each test you conduct!