Intracellular Mg2+ is important for mediating enzymatic reactions, DNA synthesis, hormonal secretion, and muscular contraction. To facilitate the investigation of magnesium’s role in these and other cellular functions, Molecular Probes® fluorescent indicators are designed to deliver ratiometric or intensity-based signals for reporting Mg2+ concentration using UV or visible excitation.
Indicators for Magnesium
Measurements using fluorescent Mg2+ indicators are somewhat more demanding than intracellular Ca2+ determinations because physiological changes in Mg2+ concentration are relatively small—but Mg2+ indicators are generally designed to maximally respond to the Mg2+ concentrations commonly found in cells, typically ranging from about 0.1 mM to 6 mM.
CHO-M1 cells loaded with 5 µM Mag-Fura-2.
Magnesium indicators are useful for measuring relief of NMDA channel blockade and entry through L-type Ca2+ channels in cardiac excitability.
|Readout||Ion-dependent spectral shift enables ratiometric determination of Mg2+ concentration||Increase in fluorescence with Mg2+ binding|
|Range||High affinity for Mg2+||Highest affinity for Mg2+|
|Standard filter set||Ratiometric and UV excitable, detect at 510||FITC|
|Ex/Ex (nm)||369/511 to 330/491||~506/531|
|Cell permeant or impermeant?||Impermeant||Permeant||Impermeant||Permeant|
|Platforms||Imaging||Flow cytometry, microplate, imaging||Imaging||Flow cytometry, microplate, imaging|
|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||20 x 50 µg|
|Molecular Probes® Handbook