Eosin-5-isothiocyanate is a good photosensitizer and can be used to selectively label amines. It has a quantum yield of 0.57 for singlet oxygen generation, which makes it useful for photoconversion of electron-rich materials such as diaminobenzidine (DAB) or fluorescent dyes into highly electron-dense materials for high resolution electron microscopy studies (1,2). Additionally, eosin is a good fluorescence acceptor for fluorescein (FAM), dansyl and coumarin dyes in fluorescence resonance energy transfer (FRET).
- λEx/λ Em (pH9) = 521/544 nm
- λµ = 95,000
- Orange red solid soluble in DMF or DMSO
- Store at -20°C and protect from light
- MW: 704.96