Fluorone dyes

yellow pigment

mixture of isomers

Calcein, also known as fluorexon, fluorescein complex, is a fluorescent dye with excitation and emission wavelengths of 495 and 515 nm, respectively, and has the appearance of orange crystals. Calcein self-quenches at concentrations above 70 mM and is commonly used as an indicator of lipid vesicle leakage. It has also been traditionally used as a complexometric indicator for titration of calcium ions with EDTA, and for fluorometric determination of calcium.

Phloxine B (commonly known simply as phloxine) is a water-soluble red dye used for coloring drugs and cosmetics in the United States and coloring food in Japan. It is derived from fluorescein, but differs by the presence of four bromine atoms at positions 2, 4, 5 and 7 of the xanthene ring and four chlorine atoms in the carboxyphenyl ring. It has an absorption maximum around 540 nm and an emission maximum around 564 nm. Apart from industrial use, phloxine B has functions as an antimicrobial substance, viability dye and biological stain. For example, it is used in hematoxylin-phloxine

chemical compound

Dichlorofluorescein (DCF) is an organic dye of the fluorescein family, being substituted at the 2 and 7 positions by chloride.