The SK10 monoclonal antibody specifically recognizes a class II major histocompatibility complex (MHC) antigen, with a molecular weight of 26 to 34 kDa, distinct from HLA-DR3-5 and HLA-DP5 antigens. Anti-HLA-DQ recognizes a common polymorphic epitope present on HLA-DQ molecules of cells expressing DQw1 and DQw3 (usually associated with DR1, DR2, DR4, DR5, DRw8, DRw9, and DRw10) and absent from DQw2 (usually associated with DR3, and DR7). Therefore, the SK10 antibody not react with cells from DR3 or DR7 homozygotes or DR3/7 heterozygotes. The HLA-DQ antigen is present on approximately 10% of peripheral blood lymphocytes. HLA-DQ reacts weakly with most peripheral blood monocytes and mitogen-stimulated T-lymphocyte blasts. The SK10 antibody reacts with virtually all B-cell lines, some myelomas, and some myeloid leukemias, but only rarely with T-lymphocyte tumors.
The antibody was conjugated to BD Horizon™ BUV737 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 737-nm. BD Horizon Brilliant BUV737 can be excited by the ultraviolet laser (355 nm) and detected with a 740/35 filter. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into channels detecting Alexa Fluor® 700-like dyes (eg, 712/20-nm filter).
Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BUV737 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV737 reagents (eg, CD4 vs. CD45) can have slightly different fluorescence spillover therefore, it may also be necessary to use clone specific compensation controls when using these reagents.