The B3 monoclonal antibody specifically recognizes the human variable γ9 subunit (Vγ9) of γ/δ T-cell receptor (TCR). The γ/δ TCR is composed of two disulfide-linked glycoproteins. The gamma chain is approximately 45-60 kD and is detected on a small subset peripheral blood T cells and thymocytes. The majority of normal peripheral blood γ/δ T cells express a Vγ9+/Vδ2+ phenotype. The reason for this selection in the T-cell repertoire is not well understood.
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.