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First Compound Microscope
Two spectacle-makers, Hans and Zacharias Janssen, constructed the first compound microscope using two lenses inside a tube. -
Robert Hooke further developed the compund microscope
He described cells as ‘… all perforated and porous, much like a honeycomb… the pores or cells… consisted of a great many little boxes…’ -
Anton van Leeuwenhoek observed unicellular organisms
described unicellular organisms from his observations of a drop of stagnant rainwater as ‘animalcules’. Leeuwenhoek also soaked some peppercorns in water for several days. When he examined a drop of this water under his microscope, he did not fi nd the little needles he expected that made pepper ‘hot’, just more unicellular organisms. 1683 Leeuwenhoek discovered bacteria -
Leeuwenhoek discovered bacteria from his observations of saliva
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René Dutrochet stated that all animals and plants are made up of cells
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Robet Brown discovered the necleus
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Matthias Schleiden and Theodor Schwann formulated the cell theory
The cell thoery is that all living matter is composed of small units called cells. -
Rudolf Virchow stated that ‘where a cell exists there must have been a pre-existing cell, just as theanimal arises only from an animal and the plant only from a plant.’
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Carl Zeiss and Ernst Abbe produced the fi rst oil immersion objectives. Images could be magnifi ed over 1000×.
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Walther Flemming described cell division (mitosis) from observations on living and stained cells.
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Ernst Ruska built the fi rst electron microscope.
Transmission electron microscopes and scanning electron microscopes were developed in the following decades. Details of internal cell structures were revealed. -
Paul Kirkpatrick and Albert Baez built the fi rst X-ray microscope that used soft X-rays.
Soft X-rays produce diffraction images that allow non-crystalline specimens, from single protein molecules to cells, to be viewed. -
Marvin Minsky developed the fi rst confocal microscope.
These laser-based scanning microscopes can produce threedimensional images of cells and cell structures. -
Two-photon fl uorescence microscope developed by Winfried Denk.
This massive microscope uses laser light that creates three-dimensional images within tissues, without damaging cells