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, Invitrogen fluorescent indicators are designed to deliver ratiometric or intensity-based signals for reporting Mg2+ concentration using UV or visible excitation. 

Select magnesium indicators

Indicators for magnesium

  • UV or visible excitation
  • Ratiometric or intensity-based measurement

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
CHO-M1 cells loaded with 5 µM Mag-Fura-2.

Magnesium indicators selection guide

Magnesium indicators are useful for measuring relief of NMDA channel blockade and entry through L-type Ca2+ channels in cardiac excitability. 

  Mag-Fura-2, Tetrapotassium Salt Mag-Fura-2, AM Magnesium Green, Pentapotassium Salt Magnesium Green, AM
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+
Fluorophore Mag-Furan-2 Magnesium Green
Standard filter set Ratiometric and UV excitable, detect at 510 FITC
Ex/Em (nm) 369/511 to 330/491 ~506/531
Bibliography Citations Citations
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
Cat. No. M1290 M1292 M3733 M3735