Rat Anti-Rituximab
R2032-24B has been used to detect rituximab bound to the surface of the Raji B cell line, however detection of rituximab bound in vivo to B-CLL cells has not been demonstrated. It is possible that complement deposition on rituximab opsonised cells inhibits binding of the Anti-Rituximab Antibody to cell bound rituximab (Beum et al. 2004). Inhibition experiments carried out with Daudi cells demonstrated that this antibody is inhibitory at a ratio of 5:1 antibody:rituximab, but does not inhibit rituximab binding to CD20 at a ratio of 1:1.
Rituximab (reference product branded as Rituxan) is a chimeric mouse/human monoclonal antibody approved for the treatment of certain autoimmune diseases and cancer, including non-Hodgkin's lymphoma, chronic lymphocytic leukemia and rheumatoid arthritis. The antibody is specific for the cell surface protein CD20, which is widely expressed on B cells. Through three different mechanisms of action it eliminates B cells from the body, enabling the development of a new population of healthy B cells.
The antibody can be used to measure the levels of rituximab and biosimilar products in bioanalytical assays.
Applications
Suitable for use in ELISA and Flow Cytometry. Other applications not tested.
Recommended Dilutions
Flow Cytometry: 50ug/ml; 10ul labels 10e6 cells in 100ul ELISA: 5ug/ml as coating antibody Optimal dilutions to be determined by the researcher.
Hybridoma
Spleen cells from immunized rats were fused with cells of the NS-1 myeloma cell line.
Recommended Negative Control
I1904-82D1: IgG2a, Rat Negative Control
Storage and Stability
May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for 12 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
Immunogen
F(ab)2 fragment of Rituximab.
Form
Supplied as a liquid in TBS, pH 8.0, 0.09% sodium azide.
Purity
Purified by Protein G affinity chromatography from tissue culture supernatant.
Specificity
Recognizes the idiotypic determinants expressed by the Rituximab humanized monoclonal antibody. Does not recognize other CD20 antibodies. Also recognizes ocrelizumab, a second-generation humanized anti-CD20 antibody that binds to an epitope on CD20 that is identical or overlapping with the rituximab epitope.
