The RUU-PL7F12 monoclonal antibody specifically recognizes CD61, a 110 kDa type I transmembrane glycoprotein, also known as Glycoprotein IIIa (gpIIIa), the common β-subunit (integrin β3-chain) of the gpIIb/IIIa complex and the vitronectin receptor (VNR). The gpIIb/IIIa complex and the VNR are integrins, ie, α/β-heterodimeric glycoprotein complexes that are involved in cell adhesion. With the CD41 antigen (gpIIb or αIIb), the CD61 antigen forms the gpIIb/IIIa complex, which acts as a receptor for fibrinogen, von Willebrand factor (vWf), fibronectin, and vitronectin on activated platelets. With the CD51 antigen (VNR α-chain or αv), the CD61 antigen forms the VNR, which mediates activation-independent cell adhesion to vitronectin, vWf, fibrinogen, and thrombospondin. The CD61 antigen is found on all normal resting and activated platelets. Platelets from individuals with Glanzmann's thrombasthenia show a >90% reduction of binding of CD61, and heterozygote carriers of the disorder show approximately 50% reduction. The CD61 antigen is also found on endothelial cells, megakaryocytes, and on some myeloid, erythroid, and T-lymphoid leukemic cell lines.
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.