The TU39 monoclonal antibody specifically recognizes human major histocompatibility (MHC) Class II HLA-DR, DP and most DQ antigens. These antigens are encoded by genes within the Human Leukocyte Antigen (HLA) Complex located on chromosome 6. MHC Class II antigens are transmembrane heterodimeric glycoproteins composed of α chain (36 kDa) and β chain (27 kDa) subunits. They are expressed primarily on antigen presenting cells which include dendritic cells, monocytes, macrophages, thymic epithelial cells, and B cells. They are also expressed on activated T cells. This molecule plays a major role in mediating cellular interactions during antigen presentation to CD4+ T lineage cells. The TU39 antibody is reportedly useful for immunophenotyping as well as functional studies including the inhibition of mixed lymphocyte reactions and antibody-mediated complement fixation on target cells.
The antibody was conjugated to BD Horizon™ BV711 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 711-nm. BD Horizon BV711 can be excited by the violet laser and detected in a filter used to detect Cy™5.5 / Alexa Fluor® 700-like dyes (eg, 712/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there may be moderate spillover into the Alexa Fluor® 700 and PerCP-Cy5.5 detectors. However, the spillover can be corrected through compensation as with any other dye combination.