Anti-Hu CD33, HIM3-4, UC, 100µg

Manufactured by STEMCELL Technologies, this monoclonal antibody is mouse IgG1, kappa, clone HIM3-4, raised against human CD33 (Siglec-3). CD33 is described as an approximately 67-75 kDa type 1 transmembrane sialoadhesion protein of the immunoglobulin superfamily, expressed on committed myeloid progenitor cells, monocytes, granulocytes, dendritic cells, mast cells, resident macrophages, and subsets of B cells and activated T and NK cells. It serves as a major marker for differentiating myeloid from lymphoid or erythroid leukemias, functions as a sialic acid-dependent cell adhesion molecule that mediates protein-glycan and protein-protein interactions between cells, and has a putative role as an inhibitory receptor during the immune response. In peripheral blood it is expressed at high levels on monocytes and at lower levels on granulocytes.

The reagent is reactive with human and chimpanzee samples and has been verified for flow cytometry, with additional applications including immunocytochemistry and immunofluorescence. It is offered in unconjugated, FITC-conjugated, and PE-conjugated formats. According to the manufacturer, HIM3-4 binds to the extracellular C2 Ig domain of CD33, does not block subsequent binding of clones P67.6, WM53, or WM54, and is reported to recognize both identified isoforms CD33M and CD33m.