Why electron microscope? Robert Hooke(1635-1703) 1 mm 于17世纪晚期设计的显微 Human eyes 镜 10 Eukaryotic cells Eukaryotic cells 10 um Prokaryotic cells Prokaryotic cells 1 um Optical microscope nig's. Viruses 100nm% Viruses Ribosomes Pneumonia 10 nm Proteins 肺炎 Ribosomes 0 1 nm mF Heavy atoms 2 Heavy atoms 100pm 颗微镜底下成串的肺炎链球菊Why electron microscope? 2 Human eyes Optical microscope Pneumonia 肺炎