The WM53 monoclonal antibody specifically recognizes CD33 which is also known as Sialic acid-binding Ig-like lectin 3 (Siglec-3) or gp67. CD33 is a 67 kDa type I transmembrane glycoprotein that is variably expressed on myeloid progenitors, monocytes, macrophages, dendritic cells, neutrophils, basophils, mast cells, and on some activated T cells and NK cells. Normal lymphocytes, platelets, erythrocytes and pluripotent hematopoietic stem cells do not express the CD33 antigen. This glycoprotein reportedly functions as a sialic acid-dependent cell adhesion molecule and this function can be modulated by endogenous sialoglycoconjugates when CD33 is expressed on the membrane.
The antibody was conjugated to BD Horizon BUV395 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. With an Ex Max near 348 nm and an Em Max near 395 nm, BD Horizon BUV395 can be excited by the ultraviolet laser (355 nm) laser and detected with a 379/28 filter. This dye has been exclusively developed by BD Biosciences as an optimal dye for use on instruments equipped with the ultraviolet laser and has virtually no spillover into any other detector.