The Human AChR-Ab (Acetylcholine Receptor Antibody) ELISA kit uses the Sandwich-ELISA principle. The micro ELISA plate provided in this kit has been pre-coated with an antigen specific to Human AChR-Ab. Samples (or Standards) are added to the micro ELISA plate wells and combined with the antigen. Then a biotinylated detection antigen specific for Human AChR-Ab and Avidin-Horseradish Peroxidase (HRP) conjugate are added successively to each micro plate well and incubated. Free components are washed away. The substrate solution is added to each well. Only those wells that contain Human AChR-Ab, biotinylated detection antigen and Avidin-HRP conjugate will appear blue in color. The enzyme-substrate reaction is terminated by the addition of stop solution and the color turns yellow. The optical density (OD) is measured spectrophotometrically at a wavelength of 450±2 nm. The OD value is proportional to the concentration of Human AChR-Ab. You can calculate the concentration of Human AChR-Ab in the samples by comparing the OD of the samples to the standard curve.