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 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 Blue™ 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.