Anti-Hu CD40, 5C3, FI, 100tests

STEMCELL Technologies offers this monoclonal antibody against human CD40. Clone 5C3 is a mouse IgG1, kappa antibody conjugated to fluorescein isothiocyanate (FITC). It was generated using recombinant full length human CD40 as immunogen and shows species reactivity with human, rhesus, cynomolgus, baboon, chimpanzee, and squirrel monkey samples, with flow cytometry (FC) listed as both a verified and a reported application.

CD40 is a 45–50 kDa type I transmembrane glycoprotein and a member of the tumor necrosis factor receptor (TNFR) superfamily. It plays an important role in B cell development and germinal center B cell selection, and facilitates T cell–B cell co-stimulation and immune regulation through engagement with CD154 (gp39), the CD40 ligand expressed on T cells. With stimuli such as IL-4, CD40 promotes B cell proliferation and immunoglobulin isotype class switching and rescues B cells from surface Ig-induced apoptosis. CD40 is expressed on B cells, follicular dendritic cells, macrophages, fibroblasts, keratinocytes, endothelial cells, basal epithelial cells, CD34+ hematopoietic progenitor cells, and primary carcinomas; it is expressed at low levels, or not at all, on plasma cells. The 5C3 antibody has been used to activate B cells in in vitro functional assays and, in the presence of IL-4 or phorbol esters, for the induction of B cell proliferation.

The product is supplied as a clear liquid in phosphate-buffered solution at pH 7.2, containing 0.09% sodium azide and 0.2% (w/v) bovine serum albumin. The antibody was purified by affinity chromatography and conjugated with FITC under optimal conditions; the solution is free of unconjugated FITC. For flow cytometry, the suggested use is ≤ 5 μL per 1 × 10^6 cells in 100 μL, with titration recommended for each application. The product is stable when stored undiluted at 2–8°C; it should not be frozen and should be protected from prolonged exposure to light.