The KS-2 monoclonal antibody specifically recognizes the John-Milton-Hagen (JMH) blood group antigen. CD108 is a 76-80 kDa glycosylphosphatidylinositol (GPI)-linked protein. It is expressed on erythrocytes, at low levels on lymphocytes, but higher levels are detected on lymphoblasts and lymphoblastic cell lines. An adhesion function for CD108 has been suggested but this has not been demonstrated. Autoantibodies to this molecule are not uncommon and often associated with the loss of JMH antigen expression on erythrocytes.
The antibody was conjugated to BD Horizon BUV496 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 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.