XFD labeling dyes are sulfonated, water-soluble fluorescent compounds with spectral properties similar to Alexa Fluor® dyes. The numerical suffix indicates approximate excitation maximum wavelength in nanometers. Sulfonation enhances aqueous solubility and reduces aggregation-induced quenching, enabling higher degrees of labeling. The product line spans the ultraviolet to near-infrared range (346–792 nm excitation) and is compatible with standard flow cytometers, fluorescence microscopes, and microplate readers.

Immunofluorescence Microscopy: XFD-conjugated antibodies enable multicolor visualization of target antigens in fixed cells and tissues.

Flow Cytometry: XFD-labeled antibodies support surface and intracellular marker detection. The full spectral range facilitates high-dimensional phenotyping on multi-laser cytometers.

FRET Studies: XFD dye pairs (e.g., XFD488/XFD555, XFD555/XFD647) may be used as donors and acceptors for studying molecular proximity and conformational changes.

Super-Resolution Microscopy: XFD647 and far-red dyes exhibit photoswitching behavior for STORM/dSTORM techniques.

In Vivo Imaging: Near-infrared dyes (XFD750, XFD790) benefit from reduced tissue autofluorescence and increased penetration depth.