Table 19.5 Response of fura-2 and indo-1 to some divalent cations other than Ca2+ and Mg2+.

Ion Indicator Kd * Spectroscopic Effect Reference
Ba2+fura-21.4 × 10-6 MSpectra similar to Ca2+ complex; no quenchingref
Cd2+fura-21.0 × 10-12 MSpectra similar to Ca2+ complex; higher intensityref
Co2+fura-28.6 × 10-9 M>99% Quenched relative to Ca2+ complexref
Mn2+fura-22.8 × 10-9 M>99% Quenched relative to Ca2+ complexref
Pb2+fura-24.2 × 10-12 MSpectra shifted relative to Ca2+ complex; no quenchingref
Pb2+indo-13.5 × 10-11 MFluorescence quenchedref
Sr2+fura-27.6 × 10-6 MSpectra similar to Ca2+ complex; no quenchingref
Zn2+fura-23.0 × 10-9 MSpectra similar to Ca2+ complex; no quenchingref
Zn2+indo-11.6 × 10-10 MSpectra similar to Ca2+ complex; no quenchingref
* Dissociation constant reported in cited literature reference.

For Research Use Only. Not for use in diagnostic procedures.