INTRODUCTION

Rituximab is a chimeric monoclonal antibody used in the treatment of diseases characterized by abnormal or excessive B cells. Rituximab targets CD20, which is expressed on the surface of B cells, to induce apoptosis in B cells and is used in the treatment of leukemia s and lymphomas, some autoimmune disorders, and organ transplant. A quantitative method for rituximab has been developed and optimized for pharmacokinetic assessment of samples.

The Rituximab ELISA kit is designed to measure Rituximab with high specificity and enhanced sensitivity. The assay design utilizes a pair of antibodies that allows the detection of the whole Rituximab molecule in biological matrices.

PRINCIPLE OF THE ASSAY

This assay employs the sandwich enzyme immunoassay technique. Anti- Rituximab is coated onto a 96 well microplate. Calibrator, quality control samples (if desired) and test samples are pipetted into the appropriate wells. Rituximab present in biological matrices is bound by the immobilized anti- Rituximab antibody. After washing away any unbound substances, enzyme linked anti- Rituximab antibody is added to the wells. This antibody is developed and purified specifically against truncated Rituxan® (domain residing in Fc portion of the Rituxan® molecule). The plate is washed to remove any unbound antibody-enzyme reagent and a substrate solution is added to the wells for color development. The color development is proportional to the amount of Rituximab present in test samples. The color development is stopped and the intensity of the color is measured.