Click2ContactPotentiometric probes are voltage-sensitive dyes that change their spectral properties in response to electric potential changes. They allow linear measurements of the firing activity of electrically active cells: neurons, myocytes and some secretory cells. Potentiometric dyes are used to measure spatial and temporal fluctuations in potential across the membrane of single cells and large cell populations. Lumiprobe Corporation offers fast-response fluorescent potentiometric probes: Di-4-ANEPPS and Di-8-ANEPPS — for imaging functional activity of neurons and heart cells, as well as RH 237 — for imaging functional activity of mitochondria, neurons and heart cells. Lumiprobe’s Potentiometric Probes are distributed in Australia and New Zealand by Sapphire Bioscience.