The 5B11 monoclonal antibody specifically recognizes mouse CD123, the α chain subunit (IL-3Rα) of the mouse IL-3 receptor. The IL-3Rα chain is a 60-70 kD transmembrane glycoprotein that binds IL-3 with low affinity but cannot transduce signals by itself. The mouse IL-3Rα chain can complex with either of two homologous β chain subunits (βc and βIL-3) to form high-affinity heterodimeric IL-3 receptors. The βc chain is the common β chain subunit that can complex with the α subunits of the mouse IL-3R, IL-5R and GM-CSFR to form high-affinity receptors. The βIL-3 subunit can form high affinity IL-3 receptor complexes with only the IL-3Rα subunit. The βIL-3 subunit clone is specific for mouse IL-3 and binds with low affinity. The immunogen used to generate the 5B11 hybridoma was CTLL cells transfected with the mouse IL-3R alpha chain. The 5B11 antibody does not block the binding of IL-3 protein to the high affinity IL-3 receptor heterodimer.
This antibody is conjugated to BD Horizon™ BV605 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 407-nm and Em Max of 602-nm, BD Horizon BV605 can be excited by a violet laser and detected with a standard 610/20-nm filter set. BD Horizon BV605 is a tandem fluorochrome of BD Horizon BV421 and an acceptor dye with an Em max at 605-nm. Due to the excitation of the acceptor dye by the green (532 nm) and yellow-green (561 nm) lasers, there will be significant spillover into the PE and BD Horizon PE-CF594 detectors off the green or yellow-green lasers. BD Horizon BV605 conjugates are very bright, often exhibiting brightness equivalent to PE conjugates and can be used as a third color off of the violet laser.