The R19-15 antibody recognizes an epitope in the CH3 domain of mouse IgG2a, with strong reactivity to the Igh-I[a] allotype and weaker reactivity to Igh-I[b]. It does not react with other Ig isotypes. Molecular genetic analyses suggest that the Igh-I[b] allele, which encodes IgG2a[b], is derived from a locus found in several wild mouse subspecies, but not domestic mice, which encodes the IgG2c isotype.
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.