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10 Types of Microscope|| Simple to Electron Microscope Quick Revision
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Jul 16, 2023
10 Microscopes explained in 12 minutes helps you to get a basic idea about different types of microscopes used in biology. ============================================================================== 12 parts of Compound Microscope and Function https://youtu.be/4lSJHpPKkwA ============================================================================== 00:00|| What is a Simple Microscope? Applications 00:40|| Compound Microscope Principle Applications and limitations 02:20|| Darkfield Microscope Principle Applications and limitations 03:21|| Phase contrast Microscope Principle Applications and limitations 04:30|| Differential Interference Contrast Microscope Principle Applications and limitations 05:47|| Fluorescence Microscope Principle Applications and limitations 07:11|| Confocal Microscope Principle Applications and limitations 08:17|| Scanning Electron Microscopes (SEM) Principle Applications and limitations 09:45|| Transmission Electron microscopes (TEMs) Principle Applications and limitations 11:08|| Scanning Transmission Electron Microscope(STEM) Principle Applications and limitations ========================================================================== We really appreciate your support ? Thank you so much:) @biologyexams4u ▶Enroll now. Our free certificate course on Introduction to Recombinant DNA Technology https://alison.com/course/introduction-to-recombinant-dna-technology?utm_source=alison_user&utm_medium=affiliates&utm_campaign=22177687
View Video Transcript
0:00
Number 10 in the list is a magnifying glass or a symbol microscope. A magnifying glass like this
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is often considered as a symbol microscope as it is used to magnify objects that cannot be seen
0:12
with our naked eyes. It is made up of a single convex lens and the maximum magnification is 10x
0:20
So take the case of this dissection microscope. It can be also considered as a symbol microscope
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as it is made up of a single type of lens. Maximum magnification is 10x. It is used to study the
0:32
morphology of animals and plants. The downside is it is of low magnification, limited use
0:38
but it is affordable, portable and economical. So to see a cell, we need a compound microscope
0:46
A compound microscope is so called because it is made up of two lenses. This is called the ocular
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lens and this is called the objective lens. Often there are many objective
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lenses called as low power, middle power and high power based on the magnification
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Maximum magnification is 1000x or thousand times magnified. Let us see how
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this compound microscope works. So this is the light source then the light passes
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through the condenser, condenser focus the light onto the specimen then this
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objective lens magnify the specimen image then further magnification by the eyepiece. So magnification is a product of magnification of the eyepiece and
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objective. This is a most commonly used microscope starting from schools, colleges and some additional sophistication. It is also used in
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histopathology or microbiology labs. Widely used to see histopathology seeing tissues than in microbiology and also in zinc cells like viewing mitosis, meiosis
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etc. The downside is thin section, stained section is required, low resolution and
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low image contrast. It is not suitable for viewing live specimens and maximum
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magnification is limited to 1000x. This microscope is portable, economical and affordable. So this is the most commonly used type of microscope to see a cell
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Just to remind you, if you find this video useful, please make sure to subscribe
2:19
our channel. Number eight in the list is the dark field microscope. As the name
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suggests, it is a special type of microscope that is meant to see unstained
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transparent biological specimens. So this is a dark field microscope. Let us see
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how this works. So this light illuminates the specimen at an oblique angle as you see here
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which causes the specimen to appear bright against a dark background. So it's well suited to see
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specimens which are transparent like this. So this is a Daphnia, a crustacean. As you see this Daphnia
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is transparent and it is clearly visible under a dark field. The specimen appears bright
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The downside is it is limited to view transparent specimen It cannot view stained specimen It cannot view thick specimen So this is a microscope that is specifically designed to see
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transparent biological specimen that cannot be seen using a bright field microscope
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Seventh in the list is a face contrast microscope. It is used to see live specimens with low contrast
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by amplifying differences in refractive index. There are two specific components that makes
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that creates this phase contrast. The first one is called the condenser annulus and the second one
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is called the phase plate. As you see here, this condenser annulus creates a hollow cone of light
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and this phase plate converts the phase shift into a intensity shift that is detected by the
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microscope's objective thus enhancing the contrast. So when this light passes through
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this specimen, different parts of the specimen will be having a different refractive index
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So that difference is detected by the objective lens or amplified by the face plate and finally
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getting an image with greater contrast. So this is the image taken using face contrast microscope
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the downside is low resolution at the same time there is a halo effect as you see sixth in the
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list is differential interference contrast microscope it's also called as nomarsky microscope
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so it is a special type of face contrast microscope high contrast images of live
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transparent samples is provided by this microscope so in this microscope a beam polarizer is used
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this polarizer the light beam splits into two beams and pass through the
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sample slightly at different angles creating interference patterns that reveal details of the sample. So this can produce 3d like images or pseudo 3d
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images. So this is an image under DIC microscope so this is an algae so this
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is an image in face contrast microscope as you see this is an image under differential
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interference contrast microscope as you see this is having a 3d effect or pseudo 3d effect 3d like
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images downside is this 3d image may not be accurate it's more expensive compared to normal
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face contrast microscope so it is an advanced version of face contrast microscope number five
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in the list is fluorescence microscope. It is used to view fluorescently labeled live specimens in
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high contrast. So it is specifically designed to view molecules in real time or cell structures in
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real time. Based on the principle of excitation and emission of fluorescent molecules or fluorophores
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we could view specific proteins or cell structures. So this is how this microscope works
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the specimen is fluorescently labeled so there is a filter so excitation filter that excites the specimen specimen emits a light of different wavelength that is detected by
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the detector and is used to create an image so the principle is excitation and
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emission of fluorescent molecules the downside is need of fluorescent tagging of specimen it's very expensive so this is an image of mitosis as you see this
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green is the spindle fibers that is labeled using green fluorescent antibody
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and this blue is fluorescently labeled tundence chromosome using DAPI and this
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red one is the DNA that is fluorescently labeled using red fluorescent antibody
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So different cell structures can be precisely viewed using this fluorescence microscope. Fourth in the list is a confocal microscope. It's an advanced version of fluorescence
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microscope. A specific fluorescent microscope that allows obtaining three-dimensional images of the
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live sample in real time with good resolution. Illuminating a sample with a focused laser beam
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As you see, a focused laser beam is used and collecting the emitted light through a pinhole
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so that it eliminates the out of focus light and produces high resolution images of a sample
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So the difference between normal fluorescence microscope and confocal microscope, the primary
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difference is this use of pinhole that eliminate out of focus light so that we get high resolution
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three-dimensional images using confocal microscope. So this is an image using confocal
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microscope as you see this is three-dimensional at the same time has high resolution compared to a
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fluorescence image. Downside is limited number of excitation wavelengths available with common lasers
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It is expensive need for fluorescent tagging of specimen. Third in the list is the scanning
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electron microscope. As the name suggests here the illumination source is beam of electrons. It is used
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to view and yze surface at high magnification by scanning a focused beam of electrons over the
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surface of a sample. It can magnify samples up to 2 million times with high depth of focus and high
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field of view comparatively less expensive than TEM. So as you see this is a scanning electron
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microscope. So here beam of electrons is used and electron gun is used to make create electrons and
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that is focused through magnetic lens into the specimen. There are scanning coils and this
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electron scans through the surface and the scattered secondary electrons are detected by a
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detector and that is to create an image, a 3D image. So this is the image from scanning electron
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microscope. As you see, this scanning electron microscope provides a good resolution, high
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magnification three-dimensional image. This is these are images of pollen grains The depth of view is also very high The downside is it cannot view live specimens low resolution compared to TEM It often requires skilled operators and it is really expensive The
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advantage over TEM is specimen preparation is comparatively easy in the case of SEM
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And the second one in the list is transmission electron microscope or TEM. So it is used to
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observe the ultra structure of cells and tissues at high magnifications and resolutions. Even
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subcellular components, viruses, macromolecules, everything can be viewed using a TEM. Provides up
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to 10 to 50 million times magnification. As you see the electron gun forms an electron beam that
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is passed through the sample. The transmitted electrons is used to create an image on a
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fluorescent screen. Here the difference between sem and tem is here the transmitted electron
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from the specimen is used to create an image on the fluorescent screen whereas in scanning
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electron microscope it actually scans the specimen and the secondary electrons scattered from the
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specimen is used to make an image. In the case of tem this is an image from tem this is adenovirus
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so magnification is very high. The downside of TEM is it often gives two-dimensional images
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requires extremely thin samples. Specimen preparation is a tedious process. It cannot
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view live specimens less than 150 nanometer. The sample should be that much thin. Skilled operators
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are needed expensive as in the case of TEM. TEM is less expensive compared to TEM. And the final
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one in the list is a combination of SEM and TEM that is scanning transmission electron microscope
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called as STEM. It is actually a combination of SEM and TEM. TEM plus an addition of a system that
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scans a focus beam across the specimen to form the image. So real-time ysis is possible
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We will be getting the surface details at the same time, the ultra-structure details within the cell
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or a tissue. It produces high resolution images of thin samples. So a TEM is often upgraded to
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TEM using this scanning coils, then this deflection scan coils, then condenser aperture
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So some more adhesions are given to TEM to make it a TEM. We could have the benefit of both
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TEM and TEM together in a single microscope. So this is an image using TEM. This is an image of
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a pollen crane, a butyl pollen crane. The limitations are it also requires very thin samples
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It is sensitive to contamination. Skilled operators are required really expensive as both SEM and TEM
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is clubbed together into a single microscope. So these are the 10 microscopes widely used in the
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field of biological science. Hope you are benefited from this video. Please consider subscribing our
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channel. Take care, stay blessed. Thank you so much for your support. You are with biologyexams4u.com
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