BioIntersect provides a simple and quantitative assay for measuring membrane potential in live cells by flow cytometry, plate reader and fluorescence microscope. Mitochondria are critical organelle in the cell and perform 90% energy production and control cell survival (apoptosis). Unwanted changes in either of these functions can cause adverse effect on cells. Monitoring compounds for mitochondrial toxicity is a crucial element of drug toxicity screening program and toxicology studies. Mitochondria membrane potential plays an important role in energy metabolism. JC-1 dye is a sensitive marker for mitochondrial membrane potential. It exists as a monomer at low concentrations and yields green fluorescence. At higher concentrations, the dye forms aggregates that exhibit a broad excitation spectrum and an emission at ~590 nm.FCCP (carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone) is a ionophore uncoupler of oxidative phosphorylation. Treating cells with FCCP will dissipate membrane potential and JC-1 stainingTest compounds that may increase or decrease membrane potential in cells.