The DX27 monoclonal antibody specifically recognizes CD158b1 (KIRDL2/NKAT6), CD158b2 (KIRDL3/NKAT2), and CD158j (KIR2DS2/NKAT5) which are members of the Killer immunoglobulin-like receptor (KIR) family within the Ig superfamily. CD158b1 and CD158j contain two (KIR2D) Ig-like extacellular domains whereas CD158b2 contains three (KIR3D) Ig-like domains. These polymorphic CD158 molecules are expressed on natural killer (NK) cells and a subset of T cells and can recognize MHC class I molecules on target cells. They serve as either inhibitory receptors (CD158b1, CD158b2) that express immunoreceptor tyrosine-based inhibitory motifs (ITIMs) in their cytoplasmic domains or activating receptors (CD158j) that lack ITIMs.
The antibody was conjugated to BD Horizon BV421 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max near 407 nm and Em Max near 421 nm, BD Horizon BV421 can be excited by the violet laser (405 nm) and detected with a 450/50 nm filter. BD Horizon BV421 conjugates are very bright, often exhibiting a 10 fold improvement in brightness compared to Pacific BlueTM conjugates. Due to nearly identical excitation and emission properties but different spillover characteristics, BD Horizon BV421, Pacific Blue, and BD Horizon V450 cannot be used simultaneously.