Morelle B, Salmon J M, Vigo J, Viallet P
Laboratoire de Chimie-Physique, Université de Perpignan, France.
Cell Biol Toxicol. 1994 Dec;10(5-6):339-44. doi: 10.1007/BF00755780.
The study of the physicochemical properties of Mag-indo-1, a fluorescent probe used for intracellular magnesium measurements, has shown that in a biological environment the deprotonated form of this probe is in simultaneous equilibrium with a protonated form, a protein and a magnesium-bound form. The complex emission fluorescence spectrum emitted by a single living cell was analyzed using a computerized method, allowing the evaluation of the contribution of each species of the Mag-indo-1 to the cellular fluorescence. This approach used to evaluate intracellular Mg2+ concentration has also shown the variability of the important participation of protein-bound Mag-indo-1 to the cellular fluorescence. Thus the widely used ratioing method, unable to take into account this variability, cannot afford a reliable evaluation of [Mg2+]. Whatever the technique used for investigation (microfluorimetry, flow cytometry, etc.) the evaluation of [Mg2+]i using the fluorescent probe Mag-indo-1 requires a method able to quantify, in complex fluorescence, the fluorescence intensity of the forms involved in the equilibrium with Mg2+.
用于细胞内镁测量的荧光探针Mag-indo-1的物理化学性质研究表明，在生物环境中，该探针的去质子化形式与质子化形式、蛋白质结合形式和镁结合形式同时处于平衡状态。使用计算机化方法分析单个活细胞发出的复合发射荧光光谱，从而评估Mag-indo-1的每种形式对细胞荧光的贡献。这种用于评估细胞内Mg2+浓度的方法还表明，蛋白质结合的Mag-indo-1对细胞荧光的重要参与存在变异性。因此，广泛使用的比率法无法考虑这种变异性，无法对[Mg2+]进行可靠评估。无论用于研究的技术是什么（显微荧光测定法、流式细胞术等），使用荧光探针Mag-indo-1评估[Mg2+]i都需要一种能够在复杂荧光中量化与Mg处于平衡状态的形式的荧光强度的方法。
