Principle of Assay
The Human MUSK Antibody ELISA Kit (A302943) is designed for the quantitative detection of human anti-MUSK antibodies in serum, plasma, tissue homogenates, and other biological samples. The assay uses a double-antigen sandwich ELISA format, in which the analyte measured is the antibody directed against MUSK, rather than the MUSK protein itself. Recombinant human MUSK antigen is pre-coated onto a 96-well microplate and serves as the capture reagent. Anti-MUSK antibodies present in the sample bind to the immobilized MUSK antigen through one of their antigen-binding sites. A biotinylated MUSK antigen is then added and binds to a second antigen-binding site on the captured antibody, forming an antigen–antibody–antigen sandwich complex. After removal of unbound components by washing, HRP-conjugated streptavidin is added and binds to the biotinylated MUSK antigen. Following a further wash step, TMB substrate is added, producing a blue color that changes to yellow upon addition of the acidic stop solution. The color intensity is directly proportional to the amount of anti-MUSK antibody captured in the wells. Absorbance is measured at 450 nm using a microplate reader, and the concentration of human anti-MUSK antibodies in the samples is determined by comparison with a standard curve.
