Magnesium Indicators

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 SaltMag-Fura-2, AMMagnesium Green, Pentapotassium SaltMagnesium Green, AM
ReadoutIon-dependent spectral shift enables ratiometric determination of Mg2+ concentrationIncrease in fluorescence with Mg2+ binding
RangeHigh affinity for Mg2+Highest affinity for Mg2+
FluorophoreMag-Furan-2Magnesium Green
Standard filter setRatiometric and UV excitable, detect at 510FITC
Ex/Em (nm)369/511 to 330/491~506/531
Cell permeant or impermeant?ImpermeantPermeantImpermeantPermeant
PlatformsImagingFlow cytometry, microplate, imagingImagingFlow cytometry, microplate, imaging
Usage notesLoad by microinjection, patch pipette, or pinocytic loading agentLoad in cell mediaLoad by microinjection, patch pipette, or pinocytic loading agentLoad in cell media
Format1 mg20 x 50 µg1 mg20 x 50 µg
Cat. No.M1290 M1292 M3733 M3735