Microscopy

• An electron microscope had a much higher magnification and resolving power than a light microscope. This means that it can be used to study cells in much finer detail. This has enabled biologists to see and understand many more sub-cellular structures.
• Electron microscopy was first used to study cells in 1945 when it generated the first images of eukaryotic cells.
• The first light microscopes were developed in the 17th century
• Scientists like Leeuwenhoek and Hooke used microscopes to develop our first understandings of cells
• Light microscopes use light and lenses to form a magnified image of a specimen
• Over the centuries, the design of the light microscope has evolve, increasing magnification and resolution to enhance detail
• You can see images of cells and large sub cellular structures with a light microscope, although stains are often required to highlight certain parts of cells
• The first electron microscopes were developed in the first half of the 20th century.
• Electron microscopes use beams of electrons rather than light to visualise specimens
• The wavelength of an electron beam is much smaller than that of visible light, to visualise specimens
• The wavelength of an electron beam is much smaller than visible light, which gives electron microscopes a much higher resolution and magnification
• An electron microscope has much higher magnification and resolving power than a light microscope
• Electron microscopes can be used to study cells in much finer detail, enabling biologist to see and understand many more sub cellular structures, like mitochondria
• Electron microscopes have also helped biologists develop a better understanding of the structure of the nucleus and cell membrane
• magnification = size of image / size of real object