MICROSCOPE

DEFINITIONA microscope derived from the Greek

word ‘micron’= small and ‘scopos’= to look/ see

MICROSCOPE: an instrument for viewing objects that are too small to be seen by the naked or unaided eye.

MICROSCOPY: the science of investigating small objects using such an instrument.

HISTORICAL BACKGROUND

• 1590— Hans Janssen and his son Zacharias Janssen, invented the first compound microscope.

• 1609—Galileo Galilei developed a compound microscope and he called it the "occhiolino" or "little eye."

• 1620— Christian Huygens, developed a simple 2-lens ocular system that was chromatically corrected.

ANTON VAN LEEUWENHOEK – He is commonly known as “THE

FATHER OF MICROBIOLOGY", and considered to be the first microbiologist. He is best known for his work on the improvement of the microscope and for his contributions towards the establishment of microbiology.

He discovered bacteria, free-living and parasitic microscopic protists, sperm cells, blood cells, microscopic nematodes, etc.

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MICROSCOPE USED BY ANTON VAN LEEUWENHOEK

An old pocket microscope

What you can see in the microscope?

MICROSCOPIC

MONSTERS

When viewed up close beneath the unblinking eye of the microscope, the

tiniest mites and most harmless of insects become terrifying beasts to haunt your

dreams."

Electron microscopic view of parasite

Mouth of a round worm parasite

Hook worm- seen in stools. An intestinal parasite, a parasitic disease that is common in the tropics and subtropics.

SCABIES

DIFFERENT TYPES OF MICROSCOPE

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X-RAY MICROSCOPE

NEUTRON MICROSCOPE

SCANNING HELIUM ION MICROSCOPE (SHIM OR HEIM)

SCANNING ACOUSTIC MICROSCOPE (SAM)

Electron Microscope

High level of technical skill is needed

Specimen preparation often takes

several days

Only dead and dried specimen

can be seen

All lenses are electromagnets

Very costly and heavy running cost

EXAMPLES OF ELECTRON MICROSCOPE

TRANSMISSION ELECTRON MICROSCOPY (TEM)

SCANNING ELECTRON MICROSCOPY (SEM)

SCANNING PROBE MICROSCOPES

Optical/ Light Microscope

–Techniques are simple–Specimen preparation normally

takes a few minutes to a few hours–Live and dead specimen

can be seen –Condenser, objective and eye

piece lenses are made of glass–Cheap and negligible running cost

EXAMPLES OF OPTICAL MICROSCOPE

STEREO MICROSCOPE/ BINOCULAR DISECTING

MICROSCOPE

CONFOCAL LASER SCANNING MICROSCOPE

COMPOUND MICROSCOPE— an optical instrument for forming magnified images of small objects, consisting of an objective lens with a very short focal length and an eyepiece with a longer focal length, both lenses mounted in the same tube.

SIMPLE MICROSCOPE— uses a single lens

COMPOUND MICROSCOPE— uses a set of lenses or lens

system

COMPOUND MICROSCOPE

COMPOUND MICROSCOPEOM

Mechanical Parts— used to support and adjust the parts

Magnifying Parts— used to enlarge the specimen

Illuminating Parts— used to provide light

LET’S HAVE AN EXCERCISE

ANSWERSa. COARSE ADJUSTMENT KNOBb. FINE ADJUSTMENT KNOBc. ARM OR THE NECKd. IRIS DIAPHRAGM LEVERe. FINE ADJUSTMENTf. MICROSCOPE BASEg. OCULAR or THE EYEPIECE h. BODY TUBEi. DUST SHIELDJ. OBJECTIVEk. OBJECTIVEl. STAGEm. CONDENSORn. MIRROR OR ELECTRIC LAMP