fura 2 am

Fura-2 AM is an indicator of ratiometric fluorescent Ca2+.

Mag-Fura-2 AM, a cell-permeable fluorescent compound, serves as a selective indicator for magnesium ions (Mg2+), demonstrating significant preference for Mg2+ over other bivalent ions including zinc (Zn2+), copper (Cu2+), and calcium (Ca2+). It notably exhibits over 13,000-fold greater selectivity for Mg2+ compared to Ca2+ (Mg2+Kd = 1.9 nM vs. Ca2+Kd = 25 μM). The excitation and emission peak wavelengths are 369 nm and 511 nm, respectively. Further, Mag-Fura-2 AM is utilized as an indirect measure of ATP consumption or production due to its magnesium ion sensitivity.

Fura-FF AM is a cell-permeable acetoxymethyl ester of the fluorescence calcium indicator fura-FF (potassium salt). Upon entering cells, it is hydrolyzed by intracellular esterases to produce fura-FF, a difluorinated derivative of the calcium indicator fura-2. Unlike fura-2, fura-FF has negligible magnesium sensitivity, reducing interference from this cation, and a higher calcium dissociation constant (Kd(calcium) = 6 μM for fura-FF and 0.14 μM for fura-2). The spectral properties of fura-FF are similar to those of fura-2, with fura-FF displaying excitation emission spectra of 365 514 nm in the absence of calcium and shifting to 339 507 nm in the presence of high calcium concentrations. Low affinity calcium dyes, including fura-FF, are preferred for studying compartments with high calcium concentrations, such as mitochondria, or in cell systems with relatively low calcium buffering capacities, such as neuronal dendrites and spines.

Fura Red AM, a fluorescent probe, is utilized for visualizing cytosolic [Ca(2+)] distribution in living plant tissue under an excitation wavelength of 488 nm [1].