Microscopy

3 min read · part of the full Exam Guide

Light and electron microscopes

Microscopes have developed over time. Light microscopes came first; the electron microscope, invented in the 1930s, has a much higher magnification and much higher resolving power (resolution)
Resolution is the ability to distinguish two points that are close together, so the image shows finer detail
Because of this, electron microscopes let biologists see and understand many more sub-cellular structures, such as ribosomes and the internal structure of mitochondria and chloroplasts

	Light microscope	Electron microscope
Magnification	up to about $\times 2000$	up to about $\times 2\,000\,000$
Resolution	about 200 nm	about 0.2 nm
Can see	nucleus, cell wall, chloroplasts	ribosomes, mitochondria in detail, viruses
Specimen	living or dead, in colour	dead, in a vacuum, black and white

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Light and electron microscopes
Magnification calculations
Required Practical 1: using a light microscope

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