Cal Green 1 is a cell-impermeant fluorescent calcium indicator that is characterized by high quantum yield and low phototoxicity. Its peak excitation and emission wavelengths (506 and 531 nm, respectively) are comparable to standard fluorescein dyes, making Cal Green 1 appropriate for fluorescent microscopy. Cal Green 1 is ~5-fold brighter than fluo-3 at saturating calcium levels.
Sel-green is a selective selenol fluorescent probe used for quantifying the selenocysteine (Sec) content in the selenoenzyme thioredoxin reductase, as well as imaging endogenous Sec in live HepG2 cells.