The 28-8-6 monoclonal antibody specifically recognizes the H-2K[b] and H-2D[b] MHC class I alloantigens. The reaction with H-2K[b] has been reported to be stronger than that with H-2D[b]. Its recognition of H-2D[b] is dependent upon the presence of β2 microglobulin. Cross-reactivity with an epitope on the N-terminal domains, α1 and α2, of the H-2D[d] MHC class I alloantigen has also been described. Reactivity with other haplotypes (e.g., f, k, p, q, r, s) has not been observed.
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.