The 14-4-4S monoclonal antibody specifically recognizes the I-E[k] MHC class II alloantigen. It crossreacts with cells from mice of the H-2[d], H-2[p], and H-2[r] haplotypes. Cells from mice of the H-2[b], H-2[f], H-2[g7], H-2[q], and H-2[s] haplotypes do not express I-E antigen. It has been reported that mAb 14-4-4S crossreacts with the rat MHC class II antigen RT1D.
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.