XFD790, manufactured by AAT Bioquest, is a highly efficient near-infrared fluorescent dye that is structurally similar to Alexa Fluor™ 790 (Thermo Fisher). Spectrally analogous to indocyanine green (ICG) and IRDye™ 800, XFD790 demonstrates exceptional aqueous solubility and sustained fluorescence stability over a broad pH range (pH 4–10), ensuring consistent and reproducible performance across diverse experimental conditions. Its long-wavelength emission effectively mitigates background autofluorescence, thereby enhancing signal-to-noise ratios in complex biological matrices, including tissue samples. As the longest-wavelength fluorophore in the XFD series, XFD790 offers superior spectral separation from widely used far-red fluorophores such as iFluor® 647, XFD647, and allophycocyanin (APC), facilitating precise multicolor fluorescence analyses. Furthermore, its optical properties make it an excellent candidate for small animal in vivo imaging (SAIVI) and two-color western blot applications using the LI-COR™ Odyssey™ infrared imaging system.

The maleimide derivative of XFD790 is widely used for labeling biomolecules with free thiol (SH) groups, including antibodies, proteins, thiol-modified oligonucleotides, and low molecular weight ligands. Maleimides react readily with sulfhydryl groups, forming stable thio-ether bonds between the dye and the biomolecule, facilitating robust and reliable labeling for diverse experimental applications.