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Cells Discovered
Robert Hooke designed his own microscope and discovered matter made up of what he called cells. -
Important Discoveries
Antony van Leeuwenhoek discovered bacteria, free-living and parasitic microscopic protists, sperm cells, blood cells and more. All of this from a very simple device that could magnify up to 300X. -
C.F. Wolff
C.F. Wolff proposed a general cell theory. -
New Lens
Achromatic lenses introduced now provide resolution of 1 micron or 1/1000 mm -
Nucleus
Robert Brown names the cell nucleus and suggests its importance in fertillization -
Plants
Matthias J. Schleiden published a cell theory as applied to plants. -
Cell Theory Begins
Theodor Schwann and Matthias Schleiden formally propose the "Cell Theory." -
So it Begins
Theador Schwann published a work that had the first statement of cell theory: All living things are made up of cells. -
Micrograph
Donne' publishes the first micrographs in France. -
Membranes
Robert Remak develops a method to isolate the cell membrane and proves it divides a cell -
Cells Generating
Rudolf Virchow proposed that living cells come from pre-existiong cells -
Theory of the Microscope
Ernst Abbe made clear the difference between magnification and resolution. His widely used formula to calculate resolution is based on his wave light theory. -
Addition of the Turret
Ernst Leitz microscope is introduced with a revolving mount (turret) for 5 objectives. -
Oil Immersion Lens
Introduced oil immersion lens (cedar oil) that resulted in a homogeneous optical path. -
Mitosis
Walther Flemming discovers mitosis. -
Improving
August Kohler- Microscope lamp with filters worked out light source and condenser position to obtain the best image projection. -
Coming in Ready
microtomes begin to appear for sample preparation. Up to the point specimens were prepared by sharp knives. -
Chromosomes
Walther Fleming used dyes to stain cells; he discovered rods he called “chromosomes.” -
Red, Yellow and Blue
Ernst Abbe designs apochromatic objective that brings red, yellow and blue into one focus -
The Same Number
Edouard van Beneden discovered that all organisms of the same species have the same number of chromosomes. -
Human Reproduction
Sutton proved that sperm and egg cells have one of each pair of chromosomes. -
Microscope by Zeiss
The first commercial UV microscope by Zeiss. -
More Discoveries
Fritz Zernike discovered he could view unstained cells using the phase angle of rays. -
First Electron Microscope
Max Knoll and Ernst Ruska construct the first electron microscope. -
It Gets Better
Ruska builds the first electron microscope that exceeds the resolution of the light microscope. -
Advancements
First scanning electron microscope is built. -
Industry
Siemens supplies the first commercially available electron microscope. -
Enzyme Production
George W. Beadle and Edward L. Tatum discovered that genes control the production of enzymes. -
Genetic Code
The Genetic code was discovered; scientists are now able to predict characteristics by studying DNA. -
Measuring Current
Scanning Probe Microscope is invented and works by measuring current. -
Lasers
Scanning laser confocal microscope is commercially available -
Measuring Force
Atomic Force Microscope is invented and measures force instead of current. -
To Many Animals?
Three generations of mice were cloned from the nuclei of an adult, eight identical calves were cloned, the rough draft of the human genome map was produced.
