DiO Staining Solution

DiO (3,3'-Dioctadecyloxacarbocyanine perchlorate) is a commonly used lipophilic fluorescent dye. The long-chain alkyl groups in the DiO molecule exhibit strong hydrophobicity, allowing the dye to tightly associate with the phospholipid bilayer of biological membranes through hydrophobic interactions. After incorporation into the cell membrane, DiO can laterally diffuse to gradually stain the entire cell membrane. The fluorescence intensity of unbound DiO molecules is relatively low; however, upon binding to the membrane, conformational changes occur that markedly enhance its fluorescence. When excited, DiO emits green fluorescence with a maximum excitation wavelength of 484 nm and a maximum emission wavelength of 501 nm.