The Eosinophil Derived Neurotoxin (EDN) ELISA Kit determines human EDN according to the ``sandwich'' ELISA principle. EDN in sample, standard and controls binds to monoclonal antibodies, which are coated to the microtiter plate. After a washing step, a peroxidase labeled polyclonal 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 in a microtiter plate reader. The EDN concentration can be calculated from the standard curve. Sample Types: stool, plasma, serum and urine. Range: 0 - 35 ng/ml. Sensitivity: 0.62 ng/ml. Time: 2 hours ? After activation eosinophil granulocytes segregate the cationic glycoprotein EDN (eosinophil derived neurotoxin). This 18-21 kDa single stranded glycosylated protein is also known as EPX (eosinophil protein X). Together with ECP (eosinophil cationic protein), EDN belongs to the ribonuclease superfamily1-3. EDN, however, has a 100-fold increased ribonuclease activity. EDN is also neurotoxic and not cytotoxic4,5. The activation of eosinophil granulocytes is important during the inflammatory processes in allergic reactions. Thus EDN is a marker for eosinophil activation and degranulation. The measurement of EDN in stool allows the detection of clinical or subclinical chronic inflammation in the gut. Some research has suggested that the measurement of EDN gives information on the activity of disease and the prediction of a relapse. The Eosinophil Derived Neurotoxin (EDN) ELISA Kit allows an easy, rapid and precise quantitative determination of the eosinophil derived neurotoxin in biological samples. The kit includes all reagents ready to use for preparation of the samples.