The s19.8 monoclonal antibody specifically recognizes the b and c alloantigens of β2 microglobulin, originally designated Ly-m11. β2 microglobulin is a 12 kDa protein, homologous to a single immunoglobulin constant-region domain, which is noncovalently associated with the MHC class I heavy chain. It may also associate noncovalently with CD1d in some cells types. Positive strains include C57BL/6, C57BL/10, C57BR, and C57L; whereas, A, AKR, BALB/c, C58, C3H, CBA, DBA/1, DBA/2, SJL, SWR, and 129 strains are negative.
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.