A-23187 Free Acid

A-23187, also known as Calcimycin or Calcium Ionophore III, is a calcium ionophore that rapidly equilibrates intracellular and extracellular calcium concentrations. It is commonly used for in situ calibrations of fluorescent calcium indicators. The ionophore allows Mn² to enter the cells and quench intracellular fluorescence of calcium indicators.

• White solid soluble in DMSO
• Store at 4C and protect from light
• C₂₉H₃₇N₃O₆
• MW: 523.6
• [52665-69-7]

Also see 4-bromo A-23187. Because 4-bromo A-23187 is nonfluorescent, it is preferred over the blue fluorescent A-23187 for calibrations of UV-excited Ca² indicators such as Indo-1 and Fura-2 in order to keep background fluorescence to a minimum.