Natalizumab ELISA (TYSABRI)

This Natalizumab ELISA is used as an analytical tool for quantitative determination of Natalizumab in serum, plasma and cell culture supernatant. Natalizumab is a humanized monoclonal antibody used for the treatment of Crohn`s Disease, and multiple sclerosis. Used as a monotherapy, Natalizumab is sold under the brand name Tysabri. It is an antibody against alpha-4 (_-4) integrin, which is required for white blood cells to move into organs. By interfering with the alpha-4 integrin receptor, Natalizumab reduces the transmission of immune cells into the central nervous system towards the affected organs through the blood barriers.The method employs the quantitative sandwich enzyme immunoassay technique. Antibodies to Natalizumab are pre-coated onto microwells. Samples and standards are pipetted into microwells and human Natalizumab present in the sample are bound by the capture antibody. Then, a HRP (horseradish peroxidase) conjugated anti- Natalizumab antibody is pipetted and incubated. After washing microwells in order to remove any non-specific binding, the ready to use substrate solution (TMB) is added to microwells and color develops proportionally to the amount of Natalizumab in the sample. Color development is then stopped by addition of stop solution. Absorbance is measured at 450 nm.