Examples of commonly used fluorophores are fluorescein or rhodamine. Aprotinin can be labelled with fluorescein isothiocyanate. Usually fluorescein or biotin is used as the fluorophore. During eye exam the defect is examined after staining with fluorescein dye. Eosin B is a dibromo dinitro derivative of fluorescein. Eosin Y is a tetrabromo derivative of fluorescein. On the basis of fluorescein angiography, CNV may be described as classic or occult. Ethidium bromide, fluorescein and green fluorescent protein are common tags. He experimented with solutions of fluorescein, eosin, and other dyes at various temperatures and viscosities. Diagnosis is often by slit lamp examination after fluorescein dye has been applied. Blood and other substances are sometimes detected by fluorescent reagents, like fluorescein. Merbromin is an organomercuric disodium salt compound and a fluorescein. The modification of the fluorescein moiety also allows multicolor analysis. Next the cornea is stained with 1% fluorescein. It is available as sterile single-use sachets containing lint-free paper applicators soaked in fluorescein sodium.