In vitro monitoring of live cardiomyocytes dynamics by a scanning near field optical microscope setup

We describe an original scanning near field optical microscope setup develo ped to examine rhythmically beating cardiac myocytes fully immersed in cult ure media. Scans could be halted at any point to record localized contracti on profiles, Contractions could be detected with high sub nanometric vertic al sensitivity and changed shape dramatically within adjacent sub micron-si zed areas. We believe that the spatial dependency of contractions arises be cause of system's ability to resolve the dynamic behavior of individual sub membrane actin bundles. Our results, combining imaging and real time recor ding in localized areas, reveal a new, non-invasive method for studying sub micron morphological activity in live biological samples.