SynaptoGreen™ C18 (equivalent to FM®3-25) is a membrane stain similar to their nerve terminal dyes, except that it has the longest lipophilic tail (C18). Because of its large size, it is used as a control for ion channel permeability of nerve terminal dyes.    Red solid soluble in DMSO or DMF  Ex/Em: 510/625 nm (in MeOH); 480/598 nm (in membranes)  Store desiccated at 4°C and protect from light, especially in solution  C58H105Br2N3  MW: 1004    FM is a registered trademark of Thermo Fisher Scientific.