BioVision’s Endothelin-1 (ET-1) ELISA kit is a competitive immunoassay for the quantitative determination of Endothelin-1 in biological fluids. ET-1 has identical amino acid sequence for human, mouse, rat, cow, dog, pig, and rabbit. The basal circulating level of ET-1 is reported to be < 1 to 3pg/mL but is known to be elevated in atrial and pulmonary hypertensions, atherosclerosis, congestive heart failure, cancer and variably related to lung diseases such as COPD and asthma. Samples and standards are added to wells coated with a monoclonal antibody specific for ET-1 and incubated. The plate is washed, leaving only bound ET-1 on the plate. A solution of HRP labeled monoclonal antibody to ET-1 is then added. This binds the ET-1 captured on the plate. The plate is then incubated. The plate is washed to remove excess HRP labeled antibody. TMB Substrate solution is added. The substrate generates a blue color when catalyzed by the HRP. Stop solution is added to stop the substrate reaction. The resulting yellow color is read at 450 nm. The amount of signal is directly proportional to the level of ET-1 in the sample. Sensitivity: 0.4 pg/ml (range: 0.78-100 pg/ml). The intra-Assay reproducibility is CV<10% & inter-Assay is CV<12%. Cross Reactivity: ET-1: 100%, ET-2: 21%, ET-3: 3.6%, human Big ET-1: <0.1%, rat Big ET-1: <0.1%, human Big ET-2: <0.1%, human Big ET-3 amide: <0.1%.