Topic 0 Flashcards
MICROSCOPY HISTORY
13th Century AD
Salvino D’Armate (Italy) made the first monocular glass - provided wearer with magnification to one eye.
Microscopy History
1590
Zachiariah Jansen, Hans Jansen (Dad) both Dutch
Started experimenting by mounting two lenses into a tube. This became the first compound microscope - capable of 9x power.
Microscopy History
1609
Galileo Galileo
Develops a compound microscope with a convex and concave lens.
Microscopy History
1665
Robert Hooke
Published Micrographia in 1665. It had illustrations of his observations with microscopes - HAD FIRST DESCRIPTION OF “CELLS”
Microscopy HIstory
1674
Anton van Leeuwenhoek
Made the first ‘REAL’ microscope. It had 270 x power. He used his knowledge of the grinding lenses to make greater magnification -> allowed detailed observations of bacteria.
Microscopy History
1826
Joseph Jackson Lister
Made achromatic lens to get rid of chromatic effect made by different wavelengths of light.
Microscopy History
1860’s
Ernst Abbe
Discovered Abbe sine condition (a condition that has to be met by a lens or other optical system in order to produce a sharp image) - a BREAKTHROUGH in microscopic design. Until then it was largely base don trial and error.
Microscopy History
1931
Ernst Ruska
Started to build the first electron microscope
Units of Measurement of Microscopy
1 inch in mm?
10 mm
Units of Measurement of Microscopy
1 mm in cm?
0.1 cm
Units of Measurement of Microscopy
1 mm in micrometers?
1000 micrometers
Units of Measurement of Microscopy
1 micrometer in mm?
0.001 mm
Units of Measurement of Microscopy
1 micrometer in nm?
1000 nanometers
What is the limit of light microscopy?
~0.2 micrometers
We would need more advanced equipment to get a higher resolution than about that.
Units of Measurement of Microscopy
1 nm in micrometers?
0.001 micrometers
Units of Measurement of Microscopy
1 nm in angstrom?
10 angstrom
Scale
Water molecule
width roughly 0.275 nanometers
Scale
Hemoglobin
width roughly 5 nanometers
Scale
HIV Virus
width roughly 120 nanometers
Scale
Red blood cell
width roughly 6-8 micrometers
How many hemoglobins in 1 red blood cell?
about 280 million hemoglobin molecules
Scale
Typical human cell
10 micrometers
Scale
Mitochondrion
1.0 micrometer
Scale
Lysosome
Between 1 and .1 micrometers
Scale
Ribosome
Between 0.1 and 0.01 micrometer
Scale
Plasma Membrane
A little below 0.01 micrometer
Scale
Protein molecule
A little bigger than 0.001 micrometer
Scale
Hydrogen atom
0.0001 micrometer
How small can the human eye see?
About 0.2 mm or 200 microns. Anything smaller than that, we need a microscope.
Light microscope vs. Electron Microscope
Illumination source
Light microscope = ambient light
Electron microscope = built in electron gun to see
Light microscope vs. Electron Microscope
Type of lens
Light microscope = glass lens
Electron microscope = electromagnetic lens
Light microscope vs. Electron Microscope
Magnification method
Light microscope = moving the lens
Electron microscope = focal length charged by changing current through lens coil
Light microscope vs. Electron Microscope
How to view sample
Light microscope = eye piece
Electron microscope = digital camera
Light microscope vs. Electron Microscope
Vacuum?
Light microscope = nope
Electron microscope = electron path from gun to camera under vacuum, makes electrons behave like light
Typical resolving power of light microscope?
0.22 micrometers
What is resolving power?
The smallest difference between two particles at which they can be resolved as separate particles?
What advantage does light microscopy have over electron microscopy?
Sample processing is minimal relative to electron microscopy - allows live cell imaging
What is the limit of resolution of the human eye?
100 micrometers
