Presentation on theme: " 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."— Presentation transcript:
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.
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.
1830: Joseph Jackson Lister, used weak lenses together at various distances provided clear magnification. 1878: Ernst Abbe : mathematical theory linking resolution to light wavelength 1903: Richard Zsigmondy: invents the ultramicroscope, allows for observation below the wavelength of light. 1932: Frits Xernike’s: Transparent biological materials was studied by phase-contrast microscope. 1938: Ernst Ruska: developed the electron microscope, which enhanced resolution. 1981: Gerd Binnig and Heinrich Rohrer: 3-D specimen images possible with the invention of the scanning tunneling microscope 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.
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.
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
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
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.!
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