The SR84 monoclonal antibody specifically recognizes CD49a (CD49 antigen-like family member A). CD49a is a ~200 kDa type I transmembrane molecule that is encoded by ITGA1 (Integrin subunit alpha 1). CD49a is also known as very late antigen 1α subunit (VLA-1) of the integrin family of cell adhesion molecules. CD49a associates with the integrin β1 subunit (CD29) to form the α1/β1 heterodimer (CD49a/CD29), and serves as receptor for collagen and laminin-1. It is expressed on activated T cells, monocytes, neuronal cells and smooth muscle cells. CD49a has been reported to play a role in cell attachment during the development of both the central and peripheral nervous systems.
The antibody was conjugated to BD Horizon™ BUV661 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 661-nm. BD Horizon Brilliant BUV661 can be excited by the ultraviolet laser (355 nm) and detected with a 670/25 filter and a 630 nm LP. Due to cross laser excitation of this dye, there may be significant spillover into channels detecting APC-like emissions (eg, 670/25-nm filter).
Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BUV661 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV661 reagents (eg, CD4 vs. CD45) can have slightly different fluorescence spillover therefore, it may also be necessary to use clone-specific compensation controls when using these reagents.