Editing Microscope (section)

===Electron microscopes===
{{See also|electron microscope}}
[[File:Ernst Ruska Electron Microscope - Deutsches Museum - Munich-edit.jpg|thumb|Electron microscope constructed by [[Ernst Ruska]] in 1933]]
In the early 20th century a significant alternative to the light microscope was developed, an instrument that uses a beam of [[electron]]s rather than [[light]] to generate an image. The German physicist, [[Ernst Ruska]], working with electrical engineer [[Max Knoll]], developed the first prototype electron microscope in 1931, a [[transmission electron microscope]] (TEM). The transmission electron microscope works on similar principles to an optical microscope but uses electrons in the place of light and electromagnets in the place of glass lenses. Use of electrons, instead of light, allows for much higher resolution.

Development of the transmission electron microscope was quickly followed in 1935 by the development of the [[scanning electron microscope]] by [[Max Knoll]].<ref name="knoll">{{cite journal |last=Knoll |first=Max|year=1935 |title=Aufladepotentiel und Sekundäremission elektronenbestrahlter Körper |journal=Zeitschrift für Technische Physik |volume=16|pages=467–475}}</ref> Although TEMs were being used for research before WWII, and became popular afterwards, the SEM was not commercially available until 1965.

Transmission electron microscopes became popular following the [[Second World War]]. Ernst Ruska, working at [[Siemens]], developed the first commercial transmission electron microscope and, in the 1950s, major scientific conferences on electron microscopy started being held. In 1965, the first commercial scanning electron microscope was developed by Professor Sir [[Charles Oatley]] and his postgraduate student Gary Stewart, and marketed by the [[Cambridge Instrument Company]] as the "Stereoscan".

One of the latest discoveries made about using an electron microscope is the ability to identify a virus.<ref>{{Cite journal|last1=Goldsmith|first1=Cynthia S.|last2=Miller|first2=Sara E.|date=2009-10-01|title=Modern Uses of Electron Microscopy for Detection of Viruses|journal=Clinical Microbiology Reviews|language=en|volume=22|issue=4|pages=552–563|doi=10.1128/cmr.00027-09|issn=0893-8512|pmid=19822888|pmc=2772359}}</ref> Since this microscope produces a visible, clear image of small organelles, in an electron microscope there is no need for reagents to see the virus or harmful cells, resulting in a more efficient way to detect pathogens.