An optical mapping system based on spectral shift of voltage-sensitive dyes

Recently, non-invasive optical methods to monitor transmembrane electrical potential using voltage sensitive dyes have been applied widely in the studies of normal and pathological heart rhythms and defibrillation. In the present paper, the authors measured the excitation and the emission spectra of the voltage-sensitive dyes di-4-ANEPPS bound to phospholipid bilayer membranes. And according to the spectral shift of di-4-ANEPPS, the authors presented an optical mapping system combining a DAL-SA CCD camera and a LED light source. Using this optical mapping system, the authors could record the action potential duration of the heart cells with high spatial and temporal resolutions. It can be a powerful tool in the study of cardiac arrhythmia mechanisms.