Development of Microscope and The Cell Theory

Development of the light microscope:

Hans and Zacharias Janssen were the first inventors of compound microscope (uses multiple lenses to collect light from the sample and then a separate set of lenses which is then focused into the eye piece) in 1590. They achieved this through the use of two convex lenses.

Galileo Galilei developed another compound microscope which used both concave and convex in 1609.

(1628-1694) Anton Van Leeuwnehoek with his simple microscope (microscope that only uses one lens) put the device into practical/ scientific uses. He invented his own tiny lenses in a shape of extreme curvature that has the ability to enlarge or magnify an object 270 times achieving much stronger magnification at his time discovering micro-organisms.

(1635 -1703) Robert Hooke improved Leeuwenhoek’s design by adding third lens behind the other existing two achieving the ability to increase magnification enabling to see cells of corks.

1878, Ernst Abbe uses his mathematical theory into figuring the resolution to the wave length of light.

1903, Richard Zsigmondy develops a microscope called the ‘ultramicroscope’ which allowed the study of objects below the wave length of light.

1932, Frits Zernike develops the phase contrast microscope allowing the observation of colour and or transparent biological specimens.

Development of the electron microscope:

In the 1900s alternative microscopy was discovered which used electrons rather than light to create an image and electromagnets in place of glass lenses. Ernst Ruska began to develop the first electron microscopy in 1931 (transmission electron microscope). The electrons allowed a much higher resolution of the cells than light.

Following the development of TEM microscope in 1935, the development of scanning electron microscope occurred by Max Knoll.

In 1965, Professor Sir Charles Oatley and his student Gary Stewart developed the first commercial scanning electron microscope (SEM).

Developments of microscopes over time were about magnifying as much as possible and to increase resolution quality as much as possible. Early magnification techniques using basic lens enabled us to see smaller creatures such as bees in much more detail than the human eye could perceive. Due to invention of microscopes using light and lens manipulation we could see creatures that were not known to exist such as bacteria and other microbes. As more lens (three lenses) and manipulation of light was used a much higher magnification was achieved allowing a major discovery of cells to occur. As the scientific revolution occurred the cell theories were being increasingly embraced, defying the theory of living matter appearing from non-living matter (spontaneous generation). The discovery of these basic building block/units of life changed the perception of animal and human life on Earth. Observing cells under light microscopes revealed the fact that they are living which other parts inside them work together to survive (internal organisations). The light microscope showed nucleus, cytoplasm and cell membrane within a cell, giving us an idea of how the cell was organised explaining the function and comparison of different cells showed that animals as well as plants have similar and non-similar organelles within cells. The development of microscope improved the cell resolution and much more magnification was seen, enabling us to view much smaller organelles. This allowed us to understand what each organelle does and their relation to other organelles with in cells and other cells. This allowed the a much more detailed structure, explaining chemicals uses in the cell aiding our body as a whole (such metabolism and respiration). Without the development of microscopy we would have not been able to see cells and lack a major gap in the biological world. The microscope has allowed us to view something a human is unable to see due to lack of resolution and magnification needed to view these tiny units. We would be ignorant about the structure and the importance of cell to a human being.