Human IL-9 ELISA Kit

Description

INTENDED USE 

This Human Interleukin 9 ELISA Kit is to be used for the in vitro quantitative determination of human interleukin 9 (IL-9) concentrations in serum, plasma, cell culture supernatant, and other biological fluids. This kit is intended FOR LABORATORY RESEARCH USE ONLY and is not for use in diagnostic or therapeutic procedures. 

INTRODUCTION

Interleukin 9 (IL-9) was initially discovered as a 40KD glycoprotein with T-cell growth factor activity in mice (1).  Human IL-9 gene was identified based on its remarkable homogeneity with the gene of mouse IL-9 (2) and was mapped to chromosome 5.   Human IL-9 has been demonstrated to be a stimulator for hematopoiesis and be associated with human malignant lymphoma (3, 4, 5, 6).  In addition, IL-9 and IL-9 receptor expression was found to be implicated with autoimmune and allergic diseases (7, 8).  IL-9 has been studied as a therapeutic target for asthma (7, 9) because of its implication with the disease.  IL-9 can be produced by Th2 cells under the stimulation of TGF-b and IL-4 and has been shown to play a role in the differentiation of Th17 cells and Treg function (10, 11). 

In recent years, IL-9 has received renewed attention because a unique type of innate lymphoid cells has been identified as the main cell type that expresses IL-9 in vivo and the IL-9 secreting cells present in skin appear to be mediate inhibition of melanoma growth in mice (12,13,14,15).  The same IL-9 secreting cells have been identified in human and the cells are currently evaluated as a new tumour treatment strategy. 

This IL-9 ELISA is a ready-to-use 3.5-hour solid phase immunoassay readily capable of measuring IL-9 levels in serum, plasma, cell culture supernatant, and other biological fluids in the range of 0 to 50 pg/mL.  This assay has shown no cross-reactivity with other cytokines tested, and is expected to be used effectively for further investigations into the relationship between IL-9 and the various conditions mentioned.

PRINCIPLE OF THE ASSAY 

This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for IL-9 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and IL-9 present is bound by the immobilized antibody. After washing away unbound substances, a biotin-linked antibody specific for IL-9 is added to the wells.  Following a wash to remove unbound biotin labelled antibody, an avidin-HRPconjugate is added to each wells.  Avidin binds to biotin labelled antibody with high affinity.  AfterTMBsubstrate solution is added to the wells, colour will develop in proportion to the amount of IL-9 bound in the initial step. The colour development is stopped and the intensity of the colour is measured. 

In order to measure the concentration of IL-9 in the samples this kit includes two calibration diluents (Calibrator Diluent I for serum/plasma testing and Calibrator Diluent II for cell culture supernatant testing.)  According to the testing system, the provided standard is diluted (2-fold) with the appropriate Calibrator Diluent and assayed at the same time as the samples.  This allows the operator to produce a standard curve of Optical Density (O.D) versus IL-9 concentration (pg/mL).  The concentration of IL-9 in the samples is then determined by comparing the O.D. of the samples to the standard curve.