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 BUV661 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 661-nm. BD Horizon Brilliant BUV661 can be excited by the ultraviolet laser (355 nm) and detected with a 670/25 filter and a 630 nm LP. Due to cross laser excitation of this dye, there may be significant spillover into channels detecting APC-like emissions (eg, 670/25-nm filter).