The BC96 monoclonal antibody specifically binds to human CD25, the low-affinity alpha subunit of the Interleukin-2 Receptor (IL-2Rα), which is also known as TAC antigen. IL2RA encodes CD25 which is a 55 kDa type I transmembrane glycoprotein comprised of an extracellular region with two Complement Control Protein domains (CCP) followed by a transmembrane region and a short cytoplasmic tail. CD25 is constitutively expressed at high levels on natural T regulatory cells and variably expressed on conventional T cells and B cells and their precursors, NK cells, monocytes, and macrophages. CD25 expression can be highly upregulated upon antigenic or mitogenic stimulation of T cells or B cells. A soluble form of CD25 is found in biological fluids due to proteolytic cleavage of the extracellular region of transmembrane CD25. CD25 noncovalently associates with CD122 (IL-2Rβ chain) and CD132 (IL-2Rγ, also known as the common γ chain or γc) to form the high-affinity signal-transducing IL-2R complex (IL-2Rαβγ). This heterotrimeric receptor mediates biological activities of IL-2 which can act as a cellular activation, growth, and differentiation factor and regulator of cell viability. Analysis of CD25 expression can be used to characterize the nature of normal leucocytes in their resting states or activated during inflammatory or immune responses as well as those present in certain disease states.
The antibody was conjugated to BD Horizon BV480 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 436-nm and Em Max at 478-nm, BD Horizon BV480 can be excited by the violet laser and detected in the BD Horizon BV510 (525/40-nm) filter set. BV480 has less spillover into the BV605 detector and, in general, is brighter than BV510.