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

IPG-2 TMA is a cell-impermeable fluorescent potassium indicator. It binds to potassium (K_d = 18 mM) and displays excitation/emission maxima of 525/545 nm, respectively. IPG-2 TMA can be used in lipid membrane-free systems or liposomes or can be introduced into cells by electroporation, microinjection, or other methods. IPG-2 is also available in a cell-permeable form .