Fura-FF is a difluorinated derivative of the calcium indicator fura-2. Unlike, fura-2, fura-FF has negligible magnesium sensitivity, thus reducing interference from this cation.[1] Fura-FF also has a higher calcium dissociation constant than fura-2 (Kd(calcium) = 6 and 0.14 μM, respectively).[1],[2]However, the spectral properties of fura-FF and fura-2 are similar with fura-FF displaying excitation/emission spectra of 365/514 nm in the absence of calcium, with a shift to 339/507 nm in the presence of a high calcium concentration.[3] Low affinity calcium dyes, including fura-FF, are preferred for studying compartments with high concentrations of calcium, such as mitochondria, or in cell systems that have relatively low calcium buffering capacities, such as neuronal dendrites and spines.[4],[5[,[6]

192140-58-2

C28H23F2K5N3O14

858.987

Fura-FF (potassium salt)

H2O:Soluble
Powder: -20°C for 3 years
In solvent: -80°C for 2 years