ToolsTechniques Used by the Biologist

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Tools/Techniques Used by the Biologist
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Simple Microscope
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Early Compound Microscopes
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More recent models. . .
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Our newest microscopes . . .
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Microtome
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Phase-Contrast Microscopy
A large spectrum of living biological specimens
are virtually transparent when observed in the
optical microscope under bright-field
illumination.
To improve visibility and contrast in such
specimens, microscopists often reduce the opening
size of the substage condenser iris diaphragm,
but this maneuver is accompanied by a serious
loss of resolution and the introduction of
diffraction artifacts. Phase contrast was
introduced in the 1930's for testing of telescope
mirrors, and was adapted by Zeiss laboratories
into a commercial microscope several years later.
This technique provides an excellent method of
improving contrast in unstained biological
specimens without significant loss in resolution,
and is widely utilized to examine dynamic events
in living cells.
Butterfly wing Scales
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Stereomicroscope
A coin as seen under a stereomicroscope.
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Transmission Electron Microscope (TEM)
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Scanning Electron Microscope (SEM)
Snowflake
Red blood cells
Stomata
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Centrifugation
Ultracentrafuge separate cell parts
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Microdissection
Laser Capture Microdissection
Chromosome Microdissection
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Tissue Culture
Plant tissue culture is a technique for the
propagation of plants under controlled laboratory
conditions. Plant parts are cleaned of all
bacteria, fungi and insects and then placed into
sterilized test tubes or other containers with
the nutrients necessary for growth of the plant.
By manipulating plant hormones included in the
nutrients, it is possible to encourage shoot
growth and subsequently root growth.
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Paper Chromatography
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More types of chromatography. . .
Column chromatography
Liquid chromatography for separating proteins
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Gas Chromatography
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Electrophoresis
Gel electrophoresis
Agarose gel electrophoresis is a method used in
molecular biology to separate DNA strands by
size, and to estimate the size of the separated
strands by comparison to known fragments (DNA
ladder). This is achieved by pulling negatively
charged DNA molecules through an agarose matrix
with an electric field. Shorter molecules move
faster than longer ones.
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Spectrophotometry
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CAT Scan
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Computerized Axial Tomography
A CAT scan, uses special x-ray equipment to
obtain image data from different angles around
the body, and then uses computer processing of
the information to show a cross-section of body
tissues and organs. CT imaging is particularly
useful because it can show several types of
tissue - lung, bone, soft tissue, and blood
vessels - with great clarity. Using specialized
equipment and expertise to create and interpret
CT scans of the body, radiologists can more
easily diagnose problems such as cancers,
cardiovascular disease, infectious disease,
trauma, and musculoskeletal disorders. This is
a patient-friendly exam that involves little
radiation exposure.
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MRI Magnetic Resonance Imaging
Magnetic Resonance Imaging or MRI creates images
similar to CT without the use of X-rays. Instead
MRI uses a strong magnetic field and radio waves
to produce detailed images of the body in
multiple planes. MRI is commonly used for
viewing the spine, brain, joints, bones, soft
tissues and blood vessels. Some exams may require
the administration of an intravenous injection of
a contrast agent.
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Open MRI
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Often tools/techniques are used by the biologist
to separate and/or identify the parts of
something. Can you name which ones do this?