The 2D9 monoclonal antibody recognizes C57BL/6 mouse Natural killer cell receptor P1D (NKR-P1D) which is also known as NKR-P1B[B6], or CD161b. CD161b is encoded by Klrb1b (killer cell lectin-like receptor subfamily B member 1B). CD161b is expressed by a functionally distinct subset of natural killer (NK) cells that express higher levels of cytotoxicity and interferon-γ (IFN-γ) than their CD161b-low or -negative counterparts. CD161b is a type II transmembrane glycoprotein that contains an immunoreceptor tyrosine-based inhibitory motif in its cytoplasmic domain. CD161b binds to C-type lectin related protein b (Clr-b) and may play a role in regulating NK cell responses. The 2D9 antibody has slight crossreactivity with cells transfected with Klrb1a/NKRP1A, Klrb1c/NKRP1C, or Klrb1f/NKRP1F.
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.