ANNINE-6plus is a water soluble voltage sensitive dye (also called potentiometric dyes). This compound was developed at the Max Planck Institute for Biochemistry in Germany.[1] It is used to optically measure the changes in transmembrane voltage of excitable cells, including neurons, skeletal and cardiac myocytes.
ANNINE-6plus has a fractional fluorescent intensity change (ΔF/F per 100 mV change) of about 30% with single-photon excitation (~488 nm) and >50% with two-photon excitation (~1060 nm).
ANNINE-6plus has been applied in the microscopic imaging of action potentials of cardiomyocyte in perfused mice heart.[2] Using confocal microscopy in conjunction with ANNINE-6plus, single sweep action potentials with high peak signal-to-noise ratio (SNR) have been recorded from single transverse tubule (t-tubule) of a few micrometers in the ventricular cardiomyocyte.