HUMAN IL-6 ELISA

BRAND:                  DEMEDITEC DIAGNOSTICS GMBH

PRODUCT CODE: DE4640

AVAILABILITY:      IN STOCK

DESCRIPTION

• CE certified for IVD use

• 96 well ELISA microplate

• Incubation time: 2 h 15 min

• Range: 25.7 - 2,760 pg/ml

• Sensitivity: 2 pg/ml

• Sample size: 100 µl

• Sample type: serum

• Substrate: TMB 450nm

1. INTENDED USE

Immunoenzymetric assay for the in vitro quantitative measurement of human interleukin-6 (IL-6) in serum.

2. CLINICAL BACKGROUND

A. Biological activities

Human Interleukin 6 (IL-6) is a 184 A.A. polypeptide with potential O and N-glycosylation sites, and a significant homology with G-CSF. It is produced by various cells, including T- and B-cells, monocytes, fibroblasts, keratinocytes, endothelial cells, mesangial cells, astrocytes, bone marrow stroma cells and several tumor cells. It regulates the growth and differentiation of various cell types with major activities on the immune system, hematopoïesis, and inflammation. These multiple actions are integrated within a complex cytokine network, where several cytokines induce (IL-1, TNF, PDGF, IFNs,...) or are induced by IL-6 and the final effects result from either synergistic or antagonistic activities between IL-6 and the other cytokines (IL-1, IL-2, IL-4, IL-5,IFNγ, IL-3, GM-CSF, M-CSF,CSF,...). IL-6 induces final maturation of B-cells into antibody producing cells and is a potent growth factor for myeloma/plasmacytoma cells. It (co-) stimulates T-cell growth and cytotoxic T-cell differentiation. Itpromotes megakaryocyte development and synergizes with other cytokines to stimulate multipotent hematopoïetic progenitors. It can also induce differentiation and growth inhibition of some leukemia -or non hematopoïetic tumoral cell lines. IL-6 is also a major inducer of the acute phase reactions in response to inflammation or tissue injury. Along with IL-1 and TNF, it induces the synthesis of acute phase proteins (APP) by hepatocytes, each cytokine or combination of cytokines showing a preferential pattern of APP production. IL-6 also interacts with the neuroendocrine system, e.g. by inducing ACTH production. Thus, IL-6 is a pleiotropic cytokine with multiple endocrine, paracrine and possibly autocrine activities in various tissues.

B. Clinical application

Although most normal controls have undetectable levels of IL-6 in their serum, huge quantities of IL-6 are detected in severe inflammatory situations such as septicemia. The elevation of serum IL-6 precedes that of acute phase proteins, e.g. in a postoperative phenomenon, and may thus be a sensitive early parameter to investigate inflammatory conditions.

Serum IL-6 has already been described in association with surgical or traumatic tissue injuries, infectious diseases, auto-immune diseases including arthritis, graft rejection, alcoholic liver cirrhosis, malignancies, etc.

3. PRINCIPLES OF THE METHOD

The Demeditec IL-6-ELISA is a solid phase Enzyme Amplified Sensitivity Immunoassay performed on microtiterplate. The assay uses monoclonal antibodies (MAbs) directed against distinct epitopes of IL- 6. Calibrators and samples react with the capture monoclonal antibody (MAb 1) coated on microtiter well and with a monoclonal antibody (MAb 2) labelled with horseradish peroxidase (HRP). After an incubation period allowing the formation of a sandwich: coated MAb 1 – human IL-6 – MAb 2 – HRP, the microtiterplate is washed to remove unbound enzyme labelled antibody. Bound enzyme-labelled antibody is measured through a chromogenic reaction. Chromogenic solution (TMB) is added and incubated. The reaction is stopped with the addition of Stop Solution and the microtiterplate is then read at the appropriate wavelength. The amount of substrate turnover is determined colourimetrically by measuring the absorbance, which is proportional to the IL-6 concentration.

A calibration curve is plotted and IL-6 concentration in samples is determined by interpolation from the calibration curve. The use of the ELISA reader (linearity up to 3 OD units) and a sophisticated data reduction method (polychromatic data reduction) result in a high sensitivity in the low range and in an extended calibration range.