Rituximab (Mabthera) is a genetically engineered chimeric murine/human monoclonal antibody specific to CD20. CD20 is an approximately 35 KDa transmembrane phosphoprotein involved in the activation, proliferation, and differentiation of B-lymphocytes. It is absent in terminally differentiated plasma cells. The Fab domain of rituximab binds to the CD20 antigen on B-lymphocytes and the Fc domain recruits immune effector functions to induce apoptosis in B cells and is used in the treatment of leukemia s and lymphomas, some autoimmune disorders, and organ transplant. The DeQuanto Rituximab (Mabthera) PK ELISA kit is a sandwich immunoassay. The Rituximab present in the sample binds to pre coated Anti-Rituximab Antibody on polystyrene microtiter plate. Non bound or the excess substances are removed by washing. Horseradish Peroxidase (HRP) labeled antibody is added to the wells. The plate is washed to remove any unbound antibody-enzyme reagent and substrate solution is added to the wells. A color product is formed in proportion to the amount of Rituximab present in the sample or standards. The color development is stopped by addition of a stop solution. The absorbance is measured at 450 nm in a microtiter plate reader. The concentration of Rituximab in a sample can be interpolated from the standard curve.

ACCURACY AND PRECISION: Inter and intra assay precision %RE 20%

SELECTIVITY: Tested in Human Plasma Matrices

SENSITIVITY: LLOQ is 6.25 ng/ml MRD: 1/250

DILUTION LINEARITY: Tested and passes with %RE 20%

ASSAY RANGE: 800 ng/ml to 6.25 ng/ml

ASSAY TIME: 3-4 Hours