The CH3A4A7 monoclonal antibody reacts with an extracellular epitope on human CD344 which is also known as Frizzled family receptor 4 (FZD4) or Frizzled-4. CD344 is a member of the Frizzled family of proteins within the G protein-coupled receptor (GPCR) superfamily. CD344 is a receptor for Wnt proteins and participates in the activation of the Wnt/beta-catenin pathway (canonical Wnt signaling). Patients with familial exudative vitreoretinopathy (FEVR) carry mutations in Frizzled-4. This disease is characterized by retinal degeneration and hearing loss. On tissues, CD344 is almost ubiquitously expressed. CD344 is highly expressed in adult heart and skeletal muscle.
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.