Pluronic F-127 *20% solution in DMSO* is a nonionic, surfactant polyol (molecular weight approximately 12,500 daltons) that has been found to facilitate the solubilization of water-insoluble dyes and other materials in physiological media. Pluronic F-127 is commonly used to help disperse the acetoxymethyl (AM) esters of our ion indicators as well as our cell tracer dyes such as CFDA-SE.