The 268318 monoclonal antibody specifically recognizes CD204 which is also known as Scavenger receptor class A member 1 (SR-A1 or SCARA1), Scavenger receptor type A (SRA-A), Macrophage acetylated LDL receptor I and II, or Macrophage scavenger receptor types I and II. CD204 is a trimeric type II transmembrane glycoprotein that is encoded by MSR1 (Msr1 macrophage scavenger receptor 1) which belongs to the type 1 class A scavenger receptor family. The C-terminal extracellular region of CD204 contains a scavenger receptor cysteine-rich domain followed by a collagen domain and an alpha-helical coiled coil. It is expressed on monocytes, macrophages, microglia, dendritic cells, and mast cells. CD204 is involved in the uptake of various negatively-charged macromolecules including modified proteins, polysaccharides, polyribonucleic acids, and microbial products and plays a role in innate and acquired immunity.
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.