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Magnesium Probes

Ursa BioScience offers a range of water soluble highly photostable probes (dye molecules, also called fluorophores) sensitive to aqueous Magnesium (II) ions, (Mg2+).

Our probes are very bright, easy to use and provide highly reproducible results.

Our magnesium probes are offered in our standard vial format, ideal for nearly all analysis formats such as in a cuvette or in microscopy.

Magnesium 510™

Magnesium 510™ is a highly sensitive probe for dissolved magnesium ions that can be used to both detect and quantitate magnesium. The probe is readily excited from 280 – 415 nm, with an extinction coefficient of (13 600 ± 700) M-1 cm-1 at 345 nm.

figure 1

Figure 1. (A) Absorption spectra recorded for Magnesium 510™ dissolved in ethanol at different concentrations. (B) Peak absorption observed at 345 nm plotted as a function of the concentration of dye. The molar extinction coefficient is calculated from the slope to be ≈ (13 600 ± 700) M-1 cm-1. The error accounts for weighing and dilution inaccuracies. Note that the error specified in the graph is the regression error only. 


Magnesium 510™ is a turn-on fluorescence probe, meaning that the fluorescence of this probe gets dramatically brighter in the presence of dissolved magnesium, enabling you to determine magnesium in your samples with relative ease. The interaction of Magnesium 510™ with magnesium is almost instantaneous, allowing rapid and real-time measurements of magnesium fluctuations to be measured and imaged. The emission spectrum of Magnesium 510™ is centered at  ~510 nm, responding to magnesium from < 0.1 to >> 2 dye equivalents.

figure 2

Figure 2. (A) Emission spectra recorded as function of time for Magnesium 510™ after the addition of 2 molar equivalents of Mg2+. Note that the weak spectra, colored orange, was recorded just before the addition of Mg2+. After the addition of Mg2+ the emission spectra overlaps and are indistinguishable. The excitation wavelength was 390 nm and the solvent a 90:10 mixture (by volume) of EtOH:H2O. (B) Peak area for the emission band, as seen in panel A for the 2.0x sample, plotted as function of time. The data point at -5 min represents data recorded before the addition of Mg ions. (C) Peak area plotted as function of the molar ratio Mg2+/ Magnesium 510™.


Magnesium 510™ is a selective probe for dissolved magnesium ions, with much weaker responses observed for other dissolved ions.

figure 3

Figure 3. Selectivity of Magnesium 510™ towards various ions. The concentration of the dye and the metal ion were both 8.0 μM in each sample, i.e. 1 molar equivalnet of ions or 1.0x. The solvent was a 90:10 mixture (by volume) of EtOH:H2O.


For current pricing of Magnesium 510™, please visit our online store.


Mg 510

Cuvettes contining 8.0 μM Magnesium 510™ dissolved in a 90:10 mixture (by volume) of EtOH:H2O. The cuvettes are placed on an UV light box and illuminated from below at 365 nm. To the cuvette to the right is 70 μM Mg2+ added. Corresponding contour graphs can bee seen in the figure below.


Contour plots for Magnesium 510

Contour plots constructed for Magnesium 510™. The data were recorded on the samples shown in the image on the top of this column.


Ursa standard prodcut vial

Magnesium 510™ is supplied dry in a prepacked vial for easy reconstitution. Visit our Online Store for current pricing. A short video shows our reconstitution procedure.