CD21 Monoclonal Antibody (HB5), APC, eBioscience™, Invitrogen™

Description

Description: The HB5 monoclonal antibody reacts with human CD21, an approximately 145 kDa type I transmembrane protein. CD21 is expressed by mature B cells, folliculate dendritic cells and a subset of epithelial cells and is a receptor for complement component C3d and Epstein-Barr virus (EBV). CD21, in association with CD19 and CD81, participates in the multimolecular complex with BCR and is involved in B cell activation. Applications Reported: This HB5 antibody has been reported for use in flow cytometric analysis. Applications Tested: This HB5 antibody has been pre-titrated and tested by flow cytometric analysis of normal human peripheral blood cells. This can be used at 5 μL (0.03 μg) per test. A test is defined as the amount (μg) of antibody that will stain a cell sample in a final volume of 100 μL. Cell number should be determined empirically but can range from 10^5 to 10^8 cells/test. Excitation: 633-647 nm; Emission: 660 nm; Laser: Red Laser. Filtration: 0.2 μm post-manufacturing filtered.

CD21 (complement receptor 2, CR2, C3D receptor, EBV receptor) binds C3 complement fragments, especially its breakdown fragments, which remain covalently attached to complement activating surfaces or antigen. CD21 has important roles in uptake and retention of immunocomplexes, survival of memory B cells and in development and maintenance of the humoral response to T-dependent antigens. CD21 also serves as a key receptor for Epstein-Barr virus binding and is involved in targeting prions to follicular dendritic cells and expediting neuroinvasion following peripheral exposure to prions. A soluble form of the CD21 (sCD21) is shed from the lymphocyte surface and retains its ability to bind respective ligands. CD21 functions as receptor for C3d, C3dg and iC3b complement components, for EBV and for IFNalpha. CD21 binds to CD23 and associates with CD19, CD81 and Leu13 to form a large signal-transduction complex involved in B cell activation. Genetic variations in the CD21 gene are associated with susceptibility to systemic lupus erythematosus type 9 (SLEB9). Alternatively, spliced transcript variants encoding different isoforms of CD21 have been found.