Novel techniques for real-time monitoring of cGMP in living cells

Recent developments of biophysical and electrophysiological techniques have enabled researchers to monitor levels of free intracellular cGMP in real-time and in intact living cells. These techniques are based on the use of cGMP sensors, which respond to cGMP with changes in transmembrane ion current or changes in fluorescence. Here, we describe the principles of these techniques, compare them in terms of sensitivity and discuss possible application for current cell biology and physiology.