IRDye 700DX (IR700 or IRDye 700DX)

IRDye 700DX is a water-soluble silicon phthalocyanine dye with strong absorption and emission in the near-infrared range (excitation ~689 nm, emission ~699 nm). It is chemically stable, has high quantum yield especially in protein-rich environments, and is typically delivered as an NHS ester for conjugation to proteins, peptides, or oligonucleotides. IRDye 700DX is uniquely suited for near-infrared photoimmunotherapy: when conjugated to a targeting antibody or ligand, illuminated with NIR light, and in the presence of oxygen, it produces reactive oxygen species that cause rapid, localized cell death in the target cells. This technology is under investigation for highly specific cancer therapy and other conditions when paired with disease-specific targeting agents. The dye itself is inert and non-toxic unless photoactivated in targeted tissue. Its spectroscopic and photochemical properties make it a tool both for biological imaging and experimental phototherapy applications. In summary, IRDye 700DX is a fluorescent dye and photosensitizer, not a biological target. It is a chemical payload used extensively for research, diagnostics, and experimental phototherapies in conjugation with disease-targeting biomolecules.

Other names

IR700IRDye 700DX NHS esterIrdye 700DXC51A2YUX4N (UNII code)

When conjugated to a targeting biomolecule (e.g., an antibody), IRDye 700DX enables photoimmunotherapy by generating singlet oxygen and reactive oxygen species upon exposure to NIR light (~690 nm), causing localized cell membrane disruption and cell death of the target cell.