The 837535 monoclonal antibody specifically recognizes Sialic acid-binding Ig-like lectin 8 (Siglec-8) which is also known as Sialoadhesin family member 2 (SAF-2). Siglec-8 is a single-pass, type I transmembrane glycoprotein that is encoded by SIGLEC8 which belongs to the Sialic acid-binding Ig-like lectins (Siglecs) superfamily. Siglec-8 has an Ig-like V-set domain followed by two Ig-like C-type domains in its extracellular region. Its intracellular region contains an immunoreceptor tyrosine-based inhibitory motif (ITIM) and an immunoreceptor tyrosine-based switch motif (ITSM) which might contribute to inhibitory signal transduction upon engagement of this receptor. A short form of Siglec-8 that results from alternative splicing and which lacks most of the intracellular domain has also been identified. Siglec-8 is expressed on eosinophils and mast cells, and weakly on basophils. Siglec-8 appears to serve as an adhesion molecule which mediates cell-cell interactions through its binding to 6' sulfated sialyl Lewis X carbohydrate structures. Siglec-8 seems to be involved in signal transduction since engagement of Siglec-8 can induce apoptosis in eosinophils or inhibit mast cell degranulation.
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.