SynaptoGreen™ C18 (also known as FM3-25) 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.
Flyer (PDF): Nerve Terminal Dyes
MSDS (PDF): MSDS 70048, MSDS 70049