Microscope invention
- Zachariah Janssen + Hans (father)
- Compound microscope (2 lenses)
Francesco Redi/1668
- Experimented to test hypothesis
- Disproved spontaneous generation in maggots
John Needham/1745
Tried to prove SG
Attributes results to LIFE FORCE
Louis Pasteur/1859
- disproved SG
- used swan-shaped flask to show if no microbes enter nun grows
Resolution
- ability to distinguish individual objects
- greater magnification = objects less resolved
Contrast
- dark vs bright
- phase contrast microscopes enhance contrast
- makes cells clearer
Staining
- increases contrast
- shows specific cell parts
Compound Light Microscope
- light passes through specimen
- two lenser magnify image
- um used for measuring
micrometers
- um
- 1mm = 1000 um
- used for small objects
Magnification
- increases specimens apparent size
Magnification formula
Ocular Lens Magnification X Objective Lens Magnification
Field of View (FOV)
- circular region of slide visible under microscope
- higher magnification = smaller FOV
FOV under low/medium/high power calculations
- measure diameter w ruler under microscope (low)
- ratios (med/high)
FOV formula
FOV1 X MAG1 = FOV2 X MAG2
Electron Microscope (EM)
- uses beams of electrons
- rly high resolving power
- magnify up to 1,000,000X
Scanning Electron Microscope (SEM)
- produces 3D image
- used for studying detailed cell surface
Transmission Electron Microscope (TEM)
- explores internal structure of cell
Confocal Laser Scanning Microscope
- high resolution images
- 2D images assembled to create full 3D image
Scanning Tunnel Microscope
- images of molecules
