New tool to monitor membrane potential by FRET Voltage Sensitive Dye (FRET-VSD) using Spectral and Fluorescence Lifetime Imaging Microscopy (FLIM). Interest in cell engineering.

In this work, we investigated a voltage-sensitive fluorescent system to monitor membrane potential by spectral and lifetime fluorescence microscopy. A two-component FRET sensor has been designed that utilizes fluorescent phospholipids acceptor (DHPE-TRITC) bound on one side of the membrane and donor molecules (oxonol) which are sensitive to membrane potential. We used multiphoton excitation and FLIM to deliver contrast lifetimes of different line cancerous cells. These results provide new information concerning the differential response to depolarized cancerous cells from resting cells when compared to fibroblast normal cells. Given the sensitivity and the fast time response, this FRET system may be particularly useful for applications involving compression of tissues by mechanical forces.