Electron Microscope

• Uses an electron beam to ‘illuminate’ the specimen, which enables organelles (e.g.the mitochondria, ER, and membranes) to be seen in detail
• Benefits: Large depth of field (more specimens in one focus), and high resolution and magnification
• Flaws: Vacuum inside the microscope (can damagespecimen), electrons pass through; so they’re stained with an electron-dense chemical (heavy metals -always dead), also it’s large, expensive and requires training
• Transmission electron microscope: Transmits an electron beam through a thin specimen, focusing them on a screen/film, (most common electron microscope); magnification of x1,000,000 and resolutionlimit of 0.5nm
• Scanning electron microscope: Scans a fine electron beam onto a specimen and collects the electrons scattered by the surface, gives excellent 3-D images, but magnification of 10x to 500,000x and resolutionlimit of 0.5 nanometres