Description The Immuchrom Beta-Defensin 2 ELISA Kit is an immunoassay for the quantitative determination of ß-defensin 2 in human stool samples. For research use only. The group of Beta-defensins are a class of antimicrobial cationic arginine rich peptides and an integral part of the innate non-specific immune response. So far nine different ß-defensins are known in humans. This includes ß-defensin 2, which consists of 64 amino acids and has a molecular weight of 7 kDa. An intensified expression of ß-defensins take place through inflammation and micro-organisms. In Crohn's disease a deficiency of ß-defensin is observed. Due to the restricted barrier function of the intestinal mucosa, the inflammation typical for Crohn's disease can be caused by bacterial invasion. Applications inflammatory processes in the intestine integrity of the intestinal mucosa The ImmuChrom complete ß-defensin 2 kit allows an easy, rapid and precise quantitative determination of ß-defensin 2 in biological samples. The kit includes all reagents ready to use for preparation of the samples. Type Sandwich ELISA, HRP-labelled antibody Other names fecal ß-defensin 2, faecal beta-defensin II, skin-antimicrobial peptide 1, BD-2, SAP1, hBD-2 Principle of Method The ß-defensin 2-ELISA test determines human ß-defensin 2 according to the “sandwich”-principle. ß-defensin 2 in sample, standard and controls binds to antibodies, which are coated to the microtiterplate. After a washing step a peroxidase labeled detection antibody is added. A second washing step is followed by the addition of the substrate which is converted to a colored product by the peroxidase. The reaction is terminated by the addition of an acidic stop solution. The optical densities are read at 450 nm (against the reference wavelength 620 nm) in a microtiterplate reader. The ß-defensin 2 concentration can be calculated from the standard curve. Sample Types Stool Sample Volume Extraction in stick vials In a stool sample extraction vial mix 15 mg stool with 1.5 ml EXT, then vortex it until the mixture is homogenous. Transfer the resulting slurry to a plastic vial and centrifuge it for 10 min at 3000 x g. The supernatant is diluted 1:2 in sample buffer (e.g. 150 µl supernatant + 150 µl sample buffer). 100 µl of the dilution are used in the test per well. Standard Curve Calibration Range: 0.1 - 3.0 ng/ml Limit of Detection 0.009 ng/ml For the determination the zero-standard was measured 20 times. The 3-fold standard deviation was added to the mean value of the optical density. The respective concentration was read from the standard curve. Intra-assay (Within-Run) C.V.
