Abstract
Molecular biologists use a fluorescence microscope to observe intracellular ions (molecules) and study intracellular mechanisms realizing cellular functions. However, they often miss a freely moving cell from a scope of the fluorescence microscope and then discontinue observation. To overcome this problem, we developed a new microscope system, which enables us to observe intracellular ions and molecules with a fluorescent light and track the cell with a transmitted light at the same time. High-speed visual feedback control was an efficient technique for cell tracking. We demonstrated that it is possible to continuously observe intracellular Ca2+ ions of the freely moving paramecium, which is one of the fastest cells. Our microscope system should become an irreplaceable tool to investigate a frontier in molecular biology.
