The 3D7 antibody reacts with CD131, the 120 kD common β chain (βc) which is shared with the receptor complexes for human granulocyte-macrophage colony stimulating factor (GM-CSFR), interleukin-3 (IL-3R) and interleukin-5 (IL-5R). Together with the α subunit of either the IL-3R (IL-3Rα), IL-5R (IL-5Rα), or GM- CSFR (GM-CSFRα), the common β chain forms high-affinity, signaling receptors for human IL-3, IL-5 and GM-CSF, respectively. Cell surface βc are expressed by a variety of different cell types including hematopoietic progenitor cells derived from pluripotent stem cells, monocytes, neutrophils, eosinophils, basophils, endothelial cells, fibroblasts, and Langerhans cells. The immunogen used to generate this hybridoma was cells co-transfected with expression vectors which contained cDNA for the human IL-3 α and β chains.
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.