BIO 311C Lecture Notes - Lecture 8: Scanning Electron Microscope, The Sharper Image, Surface Detail
Document Summary
Reductionism - reduces complex systems to simpler components that are more manageable to study. The first microscope was created by van leeuwenhoek (1632-1723) Modern light microscopes (compound microscopes) use a beam of light to illuminate an image. Used to view fixed specimens or live cells. Enhances contrast by eliminating out-of-focus light from a fluorescence micrograph, resulting in a sharper image. Electron microscopes use a beam of electrons to illuminate an image. The ratio of an object"s image size to its real size. By using more lenses microscopes can increase magnification. This does not always mean that more detail can be seen. The amount of detail depends upon the resolving power of a microscope. Resolving power - the smallest separation at which two separate objects can be distinguished. The resolving power of a light microscope is limited by the wavelength of light. Visible light ranges from ~400 nm (blue) to ~600 nm (red)
