 Microscopy
is the technical field using
microscopes to view samples and objects
that can not be seen without unaided eye
(objects that are not within the resolution
range of the normal eye). There are three
well-known branches of microscopy:
optical, electron and scanning probe
microscopy.
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Long before , in the hazy unrecorded past, a piece of
transparent crystal thicker in the middle than at the
edges, looked through it, and discovered that it made
things look larger.
Someone also found that such a crystal would focus the
sun's rays and set fire to a piece of parchment or cloth.
Magnifiers and "burning glasses" or "magnifying glasses" are
mentioned in the writings of Seneca and Pliny the Elder,
Roman philosophers during the first century A. D.,
Spectacles were invented at the end of the 13th century.
They were named lenses because they are shaped like the
seeds of a lentil.
The earliest simple microscope was merely a tube with a
plate for the object at one end and a lens which gave a
magnification ten times the actual size. These were used
to view fleas or tiny creeping things and so were dubbed
"flea glasses.
Timeline of the Microscope
4000 years ago: Use of glass lenses and water in a
tube in China
 3500 years ago: Ancient Egyptians and Romans used
glass to magnify objects
 14th century: spectacles first made in Italy
 1590: Two Dutch spectacle-makers father-and-son
team, Hans and Zacharias Janssen, created the first
microscope.
 1667: Robert Hooke's famous "Micrographia" was
published using the microscope.
 1675: Anton van Leeuwenhoek, who used a
microscope to observe insects, bacteria and other
objects.
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1830: Joseph Jackson Lister, used weak lenses together at various
distances provided clear magnification.
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1878: Ernst Abbe : mathematical theory linking resolution to light
wavelength
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1903: Richard Zsigmondy: invents the ultramicroscope, allows for
observation below the wavelength of light.
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1932: Frits Xernike’s: Transparent biological materials was studied
by phase-contrast microscope.
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1938: Ernst Ruska: developed the electron microscope, which
enhanced resolution.
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1981: Gerd Binnig and Heinrich Rohrer: 3-D specimen images
possible with the invention of the scanning tunneling microscope
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Origin: 1656, "an instrument for viewing what is small," from Gk.
micro- (q.v.) + -skopion. "means of viewing," from skopein "look at.“
The Greeks gave us the word "microscope." It comes from two Greek
words, "uikpos," small and "okottew," view.
Robert Hooks
Microscope
Made of gold
and leather and
candle as light
source
 Compound
microscope magnified an image
by a single lens can be further magnified by a
second or more lenses.
 First microscope of Antonie van
Leeuwenhoek Father of microscope): the
specimen was mounted on the top of the
pointer, above which lay a convex lens
attached to a metal holder. The specimen
was then viewed through a hole on the other
side of the microscope and was focused using
a screw (500 lenses were prepared by
grinding gave variable magnifications)
Charles Hall,1730s: Achromatic lens was
discovered that by using a second lens of
different shape and refracting properties realign
colors with minimal impact on the magnification
of the first lens.
 Joseph Lister 1830: solved the problem of
spherical aberration (light bends at different
angles depending on where it hits the lens) by
placing lenses at precise distances from each
other.
 Ernst Leitz 1863: company, addressed a
mechanical issue with the introduction of the
first revolving turret with no less than five
objectives.
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Abbe Condenser: Abbe's work on a wave theory
of microscopic imaging developed new range of
seventeen microscope objectives - three of these
were the first immersion oil objectives
 First microtome was used to enabled thinner
samples.
 August Kohler 1893: Zeiss employee figured out
an unparalleled illumination system that is still
known as Kohler illumination corrected by using
double diaphragms
 Walter Flemming 1879: cell mitosis and
chromosomes
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 19th/20th
centuries Louis Pasteur invented
pasteurization while Robert Koch discovered
his famous or infamous postulates: the
anthrax bacillus, the Tuberculosis bacillus
and the Cholera vibrio
 Light passes directly through the specimen
and image of the specimen can see through a
series of lenses.
 Unstained specimen has little contrast while
stained specimen with dyes have high
contrast.
An image of a cell stained with fluorescent dyes during metaphase.
The mitotic spindle (green) attached to the two sets of chromosomes
(blue). All chromosomes but one are already at the metaphase plate
Bright
Dark
Polarized
 Phase
Contrast Microscope : 1900,
theoretic limit of resolution for visible light
microscopes (2000 angstroms). In 1904, Zeiss
introduced UV microscope with resolution
twice that of a visible light microscope (Not
safe)
 Fritz Zernike 1930: Viewed unstained cells
using the phase angle of rays.
 Zeiss 1941: Phase contrast Microscope
introduced to win a Nobel Prize in 1953.
 Max
Knoll and Ernst Ruska 1931: invented
the first electron microscope
 That transmits a beam of electrons (as
opposed to light) through the specimen. The
subsequent interaction of the beam of
electrons with the specimen is recorded and
transformed into an image
Ongoing gene transcription of ribosomal RNA illustrating the
growing primary transcripts. "Begin" indicates the 5’ end of
the DNA, where new RNA synthesis begins; "end" indicates
the 3’ end, where the primary transcripts are almost
complete.
 1942,
Ruska improved on the TEM by building
built the first scanning electron microscope
(SEM) that transmits a beam of electrons
across the specimen.
 microscopes that can achieve magnification
levels of up to 2 million times
 Digital Microscopes: Allow for live image
transmission to a TV or computer screen and
have helped revolutionize microphotography.
Digital microscopes simply integrate a digital
microscope camera on the trinocular port of
a standard microscope.!
A mouse fibroblast nucleus in which DNA is stained blue. The
distinct chromosome territories of chromosome 2 (red) and
chromosome 9 (green) are stained with fluorescent in situ
hybridization
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Dino Lite: In the 21st century Dino-Lite Digital
microscopes handheld. They offer low power
zoom capability with magnification up to 500x.
They have had a marked impact on industrial
inspection application