FLIPR® membrane potential dye measures changes of charges across the cell membrane, upon activation of SLC5A11. The assay allows the detection of ion channel and transporter modulation by increasing or decreasing the fluorescent signal as cellular membrane potential changes. When cells are depolarized dye enters the cells, causing an increase in fluorescent signal, conversely, cells hyperpolarization results in dye exit and decreased fluorescence (Figure 1). SLC5A11 has been identified as a Na+-coupled Myo-Inositol transporter that mediates an electrogenic transport (2 Na+, 1 Myo-inositol), eligible to be studied using the membrane potential dye.