Methanaminium, N,N,N-trimethyl-, 4,5-dichloro-9-[4-[16-(4-formyl-2-methoxyphenyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadec-7-yl]-3-methoxyphenyl]-6-hydroxy-3-oxo-3H-xanthene-2,7-dipropanoate (3:1)

IPG-1 TMA is a cell-impermeable fluorescent potassium indicator. It binds to potassium (K_d = 50 mM) and displays excitation/emission maxima of 525/545 nm, respectively, and can be used in lipid membrane-free systems or liposomes or can be introduced into cells by electroporation, microinjection, or other methods. IPG-1 TMA is also available in a cell-permeable form .