The GAP.A3 monoclonal antibody specifically recognizes the polymorphic HLA class I histocompatibility antigen, A-3 alpha chain (HLA-A3). This ~44 kDa human major histocompatibility complex (MHC) class I molecule noncovalently associates with the ~12 kDa monomorphic β2 microglobulin. Two major subtypes are encoded by HLA-A3, HLA-A3.1 and HLA-A3.2. HLA-A3 gene expression is more commonly detected in individuals from Europe and southern India. HLA-A3 is expressed on nearly all nucleated cells of HLA-A3-positive individuals. HLA-A3 functions in the presentation of antigens to CD8-positive T cells which may lead to the generation of HLA-A3-restricted cytotoxic T cells and memory T cells. When complexed with certain antigens, HLA-A3 can also bind to killer cell immunoglobulin-like receptors (KIR), such as KIR3DL2, and might regulate NK cell function.
Note: Since HLA-A3 expression varies between human populations, clone GAP.A3 staining can be donor-dependent. Based on in-house testing and current literature, individuals of European or Southern Indian descent more frequently express HLA-A3 than those of Asian descent. Data may differ between donors due to geographical variations of HLA-A3 expression.
The antibody was conjugated to BD Horizon™ BUV563 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 which has an Ex Max of 348 nm and an acceptor dye. The tandem has an Em Max at 563 nm. BD Horizon BUV563 can be excited by the 355 nm ultraviolet laser. On instruments with a 561 nm Yellow-Green laser, the recommended bandpass filter is 585/15 nm with a 535 nm long pass to minimize laser light leakage. When BD Horizon BUV563 is used with an instrument that does not have a 561 nm laser, a 560/40 nm filter with a 535 nm long pass may be more optimal. Due to the excitation and emission characteristics of the acceptor dye, there may be spillover into the PE and PE-CF594 detectors. However, the spillover can be corrected through compensation as with any other dye combination.