The TH9 antibody monoclonal antibody specifically binds to CD59, a 21 kDa glycosyl-phosphatidyl inositol-anchored cell-surface glycoprotein of the Ly-6 superfamily. CD59 is expressed by many types of non-hematopoietic cells. In the rat hematopoietic system, CD59 has been detected on erythrocytes, monocytes, and some lymphocytes, but not on platelets. Soluble CD59 is found in body fluids and urine. CD59 is a complement regulatory protein that acts late in the complement cascade to prevent formation of the membrane attack complex (MAC). Therefore, CD59 is one of several proteins whose function is to protect host tissue from complement attack. Rat CD59 binds rat and human complement components and inhibits cytolysis mediated by complement from multiple species. CD59 has also been suggested to be a ligand for CD2 and to participate in T-cell costimulation.
The antibody was conjugated to BD Horizon™ BV650 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 650-nm. BD Horizon BV650 can be excited by the violet laser and detected in a filter used to detect APC-like dyes (eg, 660/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there will be spillover into the APC and Alexa Fluor® 700 detectors. However, the spillover can be corrected through compensation as with any other dye combination.