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™ BUV496 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.