Microscopy
Microscopy is a technique for producing visible images of structures or details too small to otherwise be seen by the human eye.
With the exception of techniques such as Force microscopy and electron tunnel microscopy, microscopy usually involves the diffraction, reflection, or refraction of radiation incident upon the subject of study.
In classical light microscopy, this involves passing light transmitted through or reflected from the subject through a series of lenses, to be detected directly by the eye or imaged on a photographic plate.
There is also a form of microscopy, which works based on a very small probe, and recognizing perturbations of the end of the probe, due to electrical effects. The development of microscopy revolutionized biology by enabling the discovery of microbes. Microscopes remain an essential tool in that science.
Types
There are many types of microscopy.
White Light
Light microscopy can distinguish objects separated by down to .2 micrometers.
- Bright field
- Dark field
- Phase Contrast
- Differential Interference Contrast (DIC)
Fluorescence
This can localize and quantify specific molecules in cells.
Confocal scanning
Provides sharper images of 3D objects. This is often used with fluorescence microscopy.
Electron Microscopy
- Transmission Electron Microscopy (TEM) has a limit of resolution of 0.1 nm
- Scanning Electron Microscopy (SEM) visualizes details on the surfaces of cells and particles.
