Calcein Blue

Calcein Blue is a membrane-impermeant fluorescent dye. It is a fluorescent metal ion indicator and a cell-staining reagent widely used in biochemical, analytical and imaging applications. Calcein Blue is a metallofluorochromic indicator for EDTA titration. It exhibits strong fluorescence, typically with excitation around 360-380 nm and emission near 445-465 nm (blue fluorescence). Calcein Blue solution emits bright blue fluorescence (λem=445 nm) at pH 4-11, but no fluorescence at pH 12 or higher. The blue fluorescence of the Calcein Blue solution at pH 4-11 is quenched by metal ions such as Co, Cu, Fe, Mn, Ni, Pb and Zn. However, Calcein Blue forms a highly fluorescent complex with alkaline earth metals at pH 12 or higher. Calcein Blue forms highly fluorescent complexes with divalent metal ions such as calcium and magnesium, allowing for sensitive detection and quantification in biological samples. Spectral Data: λex 322nm, λem 445nm (in methanol).