-
Period: Jan 1, 1300 to Jan 1, 1400
Magnifying Lenses
Italian monks invent magnifying glass spectacles -
Jan 30, 1485
Glass Lenses
Leonardo Da Vinci uses glass lenses to inspect small objects and study them -
Spontaneous Generation
Before we knew about cells as well as we do today, biologist developed a theory that some animals such as worms and frogs just appeared from mud. IN the 19th century, theory was dis proven when Lois Pasteur proved that micr0o-organisms only came from other micro-organisms -
Compound Microscope
2 Dutch technicians Hans and Zacharias Janssen create the art of grinding glass lenses and create the first compound microscope -
Cork
Robert Hooke, an English scientist uses a compound microscope to study a slice of cork and observes plant cells which he describes as small honey-comb like cells -
Utricles
Italian biologist Marcello Malpighi discovers that all plants are made up of small chamber like structures (Utricles) -
Pond Microorganisms
Dutch scientist Anton van Leeuwenhoek observes unicellular organisms which he calls "animalcules" when he views pond water under a microscope -
Saliva
Leeuwenhoek discovers bacteria when studying saliva -
Period: to
Protoplasm
Czech scientist Johannes Purkinje uses the word ‘protoplasm’ for the contents inside a cell -
Cells
Henri Dutrochet, a French microscopists states that all organisms are made up of cells but it is not proven -
Period: to
Nucleus
Robert Brown, a Scottish botanist discovers the nucleus after noticing a small structure inside the cell -
The Cell Theory
German scientists Matthias Schleiden and Theodor Schwann formulated the Cell theory that all living matter
are made up of small units called cells and they are the most basic unit that made up living organisms -
Cell creation theory
German scientist Rudolph Virchow states that all new cells must be created from pre-existing cells. He observed budding of yeast and used this as evidence that cells come from pre-0existing cells. -
Louis Pasteur
Louis Pasteur flask experiment showing that micro-organisms come from pre existing -
Oil Immersion
Carl Zeiss and Ernest Abbe produced the first oil immersion objectives . images could be magnified over 1000x -
Mitosis
German scientist Walter Flemming uses biological stains to view cell division clearly and proves Virchow's statements -
Period: to
DNA
In 1953, with an image of crystalline DNA from x-ray crystallography, James Watson and Francis Crick reveal the structure of DNA -
Electron Microscope
Enest Ruska, a German scientist builds the first electron microscope. With the advances in technology, scientist are able to find out the internal cell structures. -
Phase contrast microscope
A Dutch scientist named Fritz Zernicke developes a phase contract microscope which enables living cells to be viewed more clearly. -
X-Ray microscope
Soft x-rays allow non-crystalline specimens to be viewed -
Confocal microscope
These laser based microscopes can produce 3d images of cells and cell structures