Molecular Probes® sodium indicators allow spatial and temporal resolution of Na+ concentrations in the presence of physiological concentrations of other monovalent cations. These sodium indicators exhibit an increase in green fluorescence emission intensity upon binding Na+, with little shift in wavelength.
Indicators for Sodium
Indicators are available to estimate Na+ gradients in isolated mitochondria, to measure intracellular Na+ levels, to measure Na+ efflux in cells, and, in combination with other fluorescent indicators, to correlate changes in intracellular Na+ with Ca2+ and Mg2+ concentrations, intracellular pH, and membrane potential.
CA1 pyramidal neuron in a hippocampal slice filled with SBFI delivered from a patch pipette.
Used for spatial and temporal resolution of Na+ concentration and steady-state changes in sodium concentration, especially sodium/potassium ATPase studies. Also measures sodium bursts in axons and presynaptic terminals and axon initial segments.
|Readout||Increase in green fluorescence emission intensity upon binding Na+, with little shift in wavelength||Spectral excitation shift used to estimate Na+ gradients in isolated mitochondria and intracellular Na+ levels|
|Range||Responds to a range of intracellular Na+ around 10 mM||Responds to Na+ in physiological range|
|Standard filter set||FITC||Requires excitation ratio to quantify Na+ levels|
|Ex/Em (nm)||~492/516||~340 and 380/500|
|Cell permeant or impermeant?||Impermeant||Cell permeant||Impermeant||Cell permeant|
|Usage notes||Load by microinjection, patch pipette, or pinocytic loading agent||Load in cell media||Load by microinjection, patch pipette, or pinocytic loading agent||Load in cell media|
|Format||1 mg||20 x 50 µg||1 mg||1 mg||20 x 50 µg|
|Molecular Probes® Handbook