fura-2

Fura-2 is a ratiometric fluorescent calcium indicator that can be used to detect calcium in cells. It is a pentacarboxylate that displays excitation maxima of 340 and 380 nm at high and low calcium concentrations, respectively, when the emission is fixed at 510 nm, enabling determination of ratiometric measurements of calcium influx in live cells.

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

Fura-2 is a ratiometric fluorescent calcium indicator that can be used to detect calcium in cells. [1] It is a pentacarboxylate that displays excitation maxima of 340 and 380 nm at high and low calcium concentrations, respectively, when the emission is fixed at 510 nm, enabling determination of ratiometric measurements of calcium influx in live cells.

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) . As fura-FF AM enters cells, it is hydrolyzed by intracellular esterases to produce fura-FF. 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. Fura-FF also has a higher calcium dissociation constant than fura-2 (Kd(calcium) = 6 and 0.14 μM, respectively). 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. 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.

Rhod-2 (potassium salt) is a water-soluble, red fluorescent calcium indicator. It exhibits a significant shift in fluorescence intensity upon calcium binding (ex max = 549 nm; calcium-free v. ex/em max = 552/581 nm; calcium-bound). Unlike the UV-excitable indicators fura-2 and indo-1 , there is no accompanying spectral shift.

Rhod-2 (sodium salt) is a water-soluble, red fluorescent calcium indicator. It exhibits a significant shift in fluorescence intensity upon calcium binding (ex max = 549 nm; calcium-free v. ex/em max = 552/581 nm; calcium-bound). [1][2] Unlike the UV-excitable indicators fura-2 and indo-1 , there is no accompanying spectral shift.