Chapter 2 Flashcards
are used to express the sizes of microbes
Metric Units
- one that contains only one magnifying lens
- leeuwenhoek’s simple microscope had a maximum magnifying power of about 300x
Simple Microscopes
- contains more than one magnifying lens
- because visible light is the source of illumination, a compound microscope is also referred as compound light microscope
- compound light microscopes usually magnify objects about 1,000 times
Compound microscope
Types of compound microscope
Phase contrast and fluorescence
used to observe living organisms - organisms are more easily seen because the light
refracted by living cells is different from the light refracted by the surrounding medium.
Phase Contrast
contain a built in ultraviolet (UV) light source - when the UV light strikes certain dyes and
pigments, these substances emit a longer wavelength light, causing them to glow against a dark background
Fluorescence
enable us to see extremely small microbes such as rabies and smallpox viruses.
Electron Microscope
2 types of electron microscopes
Transmission and Scanning
This microscope uses an electron gun to fire a beam of electrons through an extremely thin specime
Transmission electron microscope