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Microscopes and the Development of Cell Theory

  • Microscope

    This was when Hans and Zacharias Jansen were the inventors of the microscope. The miscroscope could only be used for opaque objects and had a magnification of about 20X.
  • Period: to

    The basic units of life

    Throughout almost 2 centuries th peple during hat time had not figured out what were the building bocks of life. In 1839 though, the people finally realized and reconized the building blocks of life.
  • Illustrations with the help of microscopes

    Illustrations with the help of microscopes
    Robert Hooke used the microscope to help him in illustrating his book, which describes the subject of the cell. Also was the first to use the word cell when looking at a piece of cork. He used a microscope power of 30X.
  • Discoveries

    Antony van Leeuwenhoek discovered bacteria, free-living and parasitic microscopic protists, sperm cells, blood cells, an more. He had use a microscope that could magnify up to 300X.
  • Microscope advancement

    Microscope advancement
    The microscope lamp with filters was invented. August Kohler had worked out a light source and condenser position to obtain the best image projection. This led to better quality of the object that was being inspected.
  • Achromatic lenses

    Achromatic lenses
    Achromatic lenses were introduced and provided resolution of 1 micron or 1/1000. This would allow objects to be seen really closely and show the detail of cells and orgnisms.
  • Cell Theory

    Cell Theory
    Theodor Schwann and Matthias Schleiden formally propose the "Cell Theory" This was one of the discovories or inventions that allowed scientist to decode life.
  • FIrst Micrographs

    Donne' published th firstmicrograph in France
  • Observation of the Microscope

    Observation of the Microscope
    Ernst Abbe published his work of the theory of the microscope. He observed that much of the design of microscopes had been trial and error. He made clear the difference between magnification and resoltion while critiscizing the practice of using eye pieces with too high a magnification as "empty magnification". His widely used formula to calculateresolution is based on his wave light theory.
  • Ernst Leitz

    Ernst Leitz
    Ernst Leitz mircroscope is introduced with a revolving mount (turret) for 5 objects.
  • Oil immersed lenses

    Oil immersed lenses
    Introduced oil mmersion lens (cedar oil) that resulted in a homogeneous optical path.
  • Discovery of Mitosis

    Discovery of Mitosis
    Walther Flemmin discovers mitosis.
  • Microtomes

    Microtomes begin to appear for sample preperation. Up to the point specimens were sharp knives.
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    Microscopy and the study of bacteria

    Louis Pasteur and Robert Koch both became engaged in microscopy and the study of bacteria.
  • Apochromatic Objective

    Apochromatic Objective
    Ernst Abbe designs appocjromatic objective (An objective in which chromatic aberration is corrected for three colors and spherical aberration is corrected for two.) that brings red, yelow, and blue into one focus. These lenses required 10 or more elements. With this final advancement in the theoretic limit of resolution for visible light microscopes had been reach. (2000 angstroms)
  • Top Quality microscopes

    The inventor or co-inventors that created apochromat immersion lenses of NA 1,50 was Hugh Powell.
  • First Commercial UV microscope

    First Commercial UV microscope
    The first commericial UV microscop was invented by Ziess. The resolution of the lenses was based on Abbe's formula ( this equation allowed people to describe a perfect optical resolution mathematicaly) is twice that of a visible light microscope.
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    Viewable unstaistand cells

    Fritz Zernike discovered that he could view unsustained cells using the phase angle of rays. It took until 1941 to bring a commercial microscope to the market.
  • First electron microscope

    First electron microscope
    Max Knoll and Ernst Ruska construct the first election microscope.
  • advancement on the electron microscope

    advancement on the electron microscope
    Ernst Ruska, after contructing the electron microscope in 1931, he decided to build upon the electron microscope by having a higher resolution that exceeds the light microscope. This microscope has an accelerating voltage of 75 kV.
  • Micrograph

    First electron micrograph of a biological sample. Long leaved sundew fixed with osmuim (The chemical element of atomic number 76, a hard, dense, silvery-white metal of the transition series.) (Picture- a weevil close up. its snout is only 100 microns wide.)
  • Contrast Microscope Invention

    Contrast Microscope Invention
    The Dutchman Zernike invented the phase contrast microscope in 1934.
  • First scanning electron built

    First scanning electron built
  • Siemens supplies the first commercially available electron microscope.

  • Scanning laser confocal microscope is commercially available

    Scanning laser confocal microscope is commercially available