Rituximab ELISA (RITUXAN)

Intended Use: This Rituximab ELISA is a rapid and easy method for the quantitative determination of Rituximab in human serum, plasma and cell culture supernatant.

Assay Background: Rituximab is a genetically engineered chimeric murine / human monoclonal IgG1 kappa antibody directed against the CD20 antigen, which is primarily found on the surface of B cells. Rituximab is used in the treatment of many lymphomas, leukemias, transplant rejection and some autoimmune disorders. Unwanted immunogenicity from rituximab can manifest itself through anti-drug antibody (ADA) responses. ADA responses can lead to allergic reactions, reduction or neutralization of the activity of the drug and in some cases cross-reactive immune responses, which could lead to serious adverse events.

Assay Principle: The method employs the quantitative sandwich enzyme immunoassay technique. Antibodies to rituximab are precoated onto microwells. Samples and standards are pipetted into microwells and human rituximab present in the sample are bound by the capture antibody. Then, a HRP (horseradish peroxidase) conjugated antirituximab is pipetted and incubated with samples. 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 rituximab in the sample. Color development is then stopped by addition of stop solution. Absorbance is measured at 450 nm.