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Microscopy Worksheet 5 50 pts
Background One of the most common instruments used in biology is the microscope. The invention of the microscope
revolutionized biology. It helped establish that living things are made of cells and that microorganisms
exist that are invisible to the naked eye. Microscopes are valuable tools in biology because they are
capable of increasing both the magnification and resolution of the observed specimen. Magnification
refers to the apparent size of the specimen, whereas resolution refers to the clarity of seeing two objects
as distinctly separate. The magnification power of a compound light microscope is determined by its ocular and the objective,
which is why we refer to the microscope as a compound light microscope
. A typical ocular has a
magnification power of ten (10X). The objectives are magnifying lenses fastened on the rotating
nosepiece. The objectives on student microscopes are 4X, 10X, 40X, and sometimes 100X (for oil
immersion). To calculate the total magnification of the specimen, one would multiply the ocular power by
the objective power as below: Total magnification = magnification of ocular X magnification of objective used We will be introducing a compound light microscope by first acquainting you with the parts and functions
of the parts of the microscope and then by viewing a variety of cell specimens. Eukaryotic cells are those
that contain a nucleus and membrane-bound organelles. Prokaryotic cells
, or bacterial cells, are much
smaller in size and do not contain a nucleus or membrane-bound organelles. MICROSCOPE FIELD OF VIEW When you look into a microscope that has the power turned on, you should see a bright circle. This bright
circle of light shows you the area of the slide that is being magnified and is called the field of view
. As
you increase objective magnification power, the field of view gets smaller. This does not mean the bright
circle that you see through the microscope becomes smaller. It simply means a smaller area of the slide is
being magnified.
Diameter of the field of view for the student light microscope. Objective Lens Diameter of the Field of View (1 mm = 1,000 μm) 4X 4.5 mm or 4,500 μm 10X 1.8 mm or 1,800 μm 40X 0.5 mm or 500 μm One can use the diameter of the field of view to estimate the size of the object that is being observed under
the microscope. To estimate the size of the object observed, use the following steps: 1.
Select a suitable magnification for size estimation. It is important that you choose a magnification that
allows you to observe the entire object. If the object is very small, use the highest magnification
available for your estimation. 2.
Place the object in the center of the field of view. Estimate the number of objects that can fit across the
diameter of the field of view. 3.
Estimated object size = Diameter of the chosen field of view ÷ Estimated number of object across the
diameter of the field of view. Virtual Labs I. Operation of bright field microscope
1.
(2 pts) What is the difference between resolution and contrast? Resolution is the ability to distinguish fine detail, while contrast is the ability to recognize objects
such as cells from a background.
2.
(1pt) What is the field of view? The field of view is the amount of the slide you are able to see through the microscope’s eyepiece.
3.
(1pt) What is the relationship between objective, magnification power and the field of view? As magnification in the microscope increases, the field of view decreases.
4.
(1pt) Total magnification = Objective lens multiplied times the 10x of the ocular lens
(Is the
overall enlargement of the image of a specimen.)
5.
(1pt) What is the total magnification of the observed objects in a microscope that is using the 40X
objective lens? The total magnification of the observed objects in a microscope that is using the 40x objective
lens would be 400x.
6.
(1pt) When using the 100X objective lens, a drop of
immersion oil is needed on the specimen slide. 7.
(1pt) How does changing light intensity affect the contrast of an image in a microscope? When the light intensity is to bright it can blind the view, so you only see white, and if it is to low, you will not be able to see anything, so it is important to adjust the light in a way where you can see every detail of the specimen.
8.
(1pt) How do you bring a specimen into focus quickly? To bring a specimen into focus quickly is better to start with a 4x objective lens and adjust the
focus with the fine adjustment knob, and after that increase the objective lenses.
II. Label the Parts and Describe the Function of the Parts of the Microscope
Directions: With the help from the last activity, and your computer, label the parts of the microscope,
listed below, and describe the function of the part next to your label.
(10 pts) 1. Mechanical Stage: where you place a specimen for viewing.
6. Rotating Nosepiece: houses and moves all the objective lenses. 2. Fine Focus Knob: moves the stage up and down slowly to sharpen the image of the specimen. 7. Objective lens: closest lens to the specimen. Magnify the image of the specimen. 3. Coarse Focus Knob: focus the image under low power magnification, move the stage up and down rapidly.
8. Oculars: adjustable piece
to place the eyes to look at the specimens. 4. Condenser: lenses used to collect and focus light from the light source into the specimen.
9. Stage adjustment knobs:
moves
the
stage
mechanically
(left,right,forwardand
backward). 5. Iris Diaphragm: controls the amount of light that reaches the specimen. 10. Light source: reflects the light from an external source to the sample.
II. Microscopy – Plant Cells (Onion Epidermal Cells) Background
All living systems are made up of either prokaryotic or eukaryotic cells. Bacteria are prokaryotic
organisms. Prokaryotic cells are generally smaller, less complex, and most importantly, the genetic material
(DNA) is not enclosed in a membrane-bound structure (known as the nucleus). All bacteria are
prokaryotes. Eukaryotic cells make up all the other kingdoms of life: plants, animals, fungi, and protists.
Eukaryotic cells are generally larger, more complex in cellular organization, and have distinct membrane-
bound structures known as organelles (including having a nucleus). Most cellular structures are too small
and colorless to be visually identifiable using a light microscope. However, it is possible to visualize nuclei
in eukaryotic cells using a light microscope. In this next simulation, you will observe onion epidermal cells, which are harvested from the inner portion of a layer from an onion bulb. The bulb of the onion grows underground so, therefore, the organelle which accomplishes photosynthesis, the chloroplast
, will not be visible in an onion bulb. Furthermore, since
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Related Questions
True or false?
light microscopy has a limit of resolution of 200nm.
phase contrast microscopy can be used to observ thick (more than 2 cells)speciments.
mammalian cells are grown in a humidified incubator at 30C and 5% CO2.
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As
ENRICHMENT CARD
THINGS TO REMEMBER:
A compound microscope like me, is an instrument used to
see organisms or objects that are too small to be seen by
the naked eye. Plant and animal cells, different kinds of
microorganisms and even mineral samples are microscopic
specimens since they are invisible to the eye. A microscope
is needed to see them. The microscope magnifies these
specimens several hundred times or more. The science of
investigating very tiny organisms and small objects using
microscope is called microscopy.
A compound microscope has magnifying parts that make the specimen look
bigger. Lenses, such as the eyepiece or ocular and the objective lenses are the
magnifying parts. There are different objective lenses; Low Power Objective
(LPO) covers a wide field of view, it usually has a 10X magnification; High Power
Objective (HPO) has a magnification of 40X or 43X is ideal for observing very
fine detail and it is usually longer than the LPO and oil immersion objective has
a…
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3D dimensionality is a limitation of the compound
microscope. Depth of field, DOF, describes dimensionality
form top to bottom and can be observed with colored cross
threads. Observe the crossed thread slide on low power
(4x), then on medium power (10x), then on high power
(40x objective magnification).
Which crossed fiber is on top?
How do you know?
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PART C: CALCULATING THE DIAMETER OF THE FIELD OF VIEW (FOV)_
The field of view (FOV) is the circular area you can see when you look through the microscope. The
diameter of the field of view is different depending on which objective lens you are using. For example,
you are using the medium-power objective lens, then the area you can see is actually smaller than if you
were using the low-power objective lens. Knowing The diameter of the field of view can help you estimate
actual size of objects / cells seen through the microscope.
When the revolving nose piece is turned to the low power objective lens, a dear plastic ruler can be placed on the microscope stage (see figure 1).
Then, the coarse adjustment knob can be used to focus on the millimeter marks of the ruler making sure that one of the milimeter marks is at the left
edge of the field of view (see figure 2).
NOTE:
Slage cip
I-1000
Objects in the FOV are usually
measured in micrometers (um).
To convert, a FOV in mm, times
it by 1000…
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Please explain the table
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The most widely used type of light microscope is the
Multiple Choice
bright-field microscope.
dark-field microscope.
phase-contrast microscope.
confocal microscope.
fluorescence microscope.
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Help with
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please check image
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Clinical microscopy
How to troubleshoot a microscope?
How to cleanup a microscope?
How to take care a microscope?
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Simulated data: Imagine you collect the following images at the above
magnifications.
Figure 3-2: Images of cheek cells at the above magnifications.
Labelling Drawing:
Label only the microscope image taken at 1000x magnification. Add lines and
labels (as per guidelines for scientific drawings). You should include:
A scale bar showing a unit length of 20 µm. (Hint: The length of the human cheek
cell shown is 60 um).
Labels for the cell membrane, nucleus, and cytoplasm.
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This is just a labster demonstration not a test, I am having trouble finding the answer in the text
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Please answer fast
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Which of the following microscopes typically requires the use of vital dyes (like methylene blue) to visualize large subcellular structures in a living cell (like the nucleolus or the mitochondrion)?
the scanning/tunneling electron microscope (STEM), with good resolution up to about 100,000,000x
the transmission electron microscope (TEM), with good resolution up to about 100,000x
the scanning electron microscope (SEM), with good resolution up to about 1,000,000x
the compound light microscope, with good resolution up to about 1,500x
all of the above microscopes would be equally useful in visualizing the interior of organelles
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Explain when to use bright-field, phase-contrast, dark-field, fluorescence, transmission electron, and scanning electron microscopy for a given situation. What is an example of this situation?
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You may want to use this resource for this problem. If you do, submit the output along with your solution.You have been given a confocal microscope equipped with the following lasers, excitation filters, andemission filters:Laser Emission filter355 nm 410-470 nm405 nm 470-500 nm488 nm 500-550 nm532 nm 570-610 nm561 nm 610-650 nm640 nm 660-700 nm808 nm 720-780 nmYour task is to design an experiment to visualize the following:1. Nuclei2. A fluorescent protein in the cytosol3. A cell membrane marker antibody conjugated with a fluorophore4. Actin filaments5. LysosomesYou may choose from the following fluorophores for each of the five channels:Nuclei Fluorescent protein Membrane marker Actin marker Lysosome trackerDAPI GFP FITC AF488 Phalloidin LysoTracker RedHoechst 33342 YFP WGA-TRITC AF568 Phalloidin LysoTracker DeepRedSYTO Deep Red RFP Cy7 AF594 Phalloidin LysoTracker Blue
Part 3.1Choose appropriate fluorophores for each of the subcellular structures to be imaged, taking into…
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What description best describes the compound light microscope?
Uses a beam of electrons is transmitted through a specimen to form an image.
Has more than one lens and its own light source. In this type of microscope,
there are ocular lenses in the binocular eyepieces and objective lenses in a
rotating nosepiece closer to the specimen.
An optical imaging technique for increasing optical resolution and contrast of a
micrograph by means of using a spatial pinhole to block out-of-focus light in
image formation.
Designed for low magnification observation of a sample, typically
using light reflected from the surface of an object rather than transmitted
through it.
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Clinical MIcroscopy
How to properly clean up a microscope?
How do you care for a microscope?
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There are many different types of microscopes that can be used in science. Research the function of each type of microscope below
Stereomicroscopes
Bright field microscope
Dark field microscope
Fluorescence microscope
Phase contrast microscope
Nomarski microscope
Scanning electron microscope
Transmission electron microscope
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what are some tips to improve image quality when looking at a organsims using a microscope
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For each type of microscopy, know how each is used and the type of image produced. kEEP IT SHORT AND SWEET
Light microscope –
Transmission electron microscope -
Scanning electron microscope –
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Microscope
You should always position the cells or tissues in the center of view before increasing magnification, because
you know that the image will move right as you move the slide to the left.
you know that the image will move up as you move the slide down
you know that the center of field of view will be unchanged
this is the best way to avoid breaking the slide with an objective
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A student has a compound microscope equipped with 10X ocular lenses and 4X, 10X,
40X and 100X objective lenses. The student has a slide with cells that are -100
microns (1 micron = 103 mm) in diameter, and wants to view a magnified image of a
%3D
cell so that the cell appears to be 10 mm in diameter. Which objective lens should
the student use?
O 10X
O 40X
O 100X
O 4X
Question 7
2 pts
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What are the differences and similarities between Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). Please explain in detail.
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SBI 3C1
VIRTUAL LAB: THE MICROSCOPE
INSTRUCTIONS: Go to the following link: https://virtuallabs.nmsu.edu/micro.php. Click the continue tab and follow the
instructions on how to properly use a microscope. When you are complete, answer the questions below.
PART A: MAGNIFICATION OF THE MICROSCOPE - How much biggerl enlarged is the specimen?
TOTAL MAGNIFICATIION (eyepiece (ocular) magnification) X (objective lens magnification)
Calculate the total magnification for each lens below for a simple COMPOUND LIGHT MICROSCOPE
ОBJECTIVE
LENS
POWER
OCULAR
MAGNIFICATION
OBJECTIVE LENS
MAGNIFICATION
TOTAL MAGNIFICATION
MAG (X) = Ocular X Objective
LOW
LP MAG =
MEDIUM
MP MAG=
HIGH
HP MAG-
Complete the following chart by calculating the missing lens or total magnification [2]
TOTAL MAGNIFICATION
OBJECTIVE LENS MAGNIR
AR (EYEPIECE)
MAGNIFICATION
5X
80X
10X
40X
10X
100X
500X
50X
PART B: HOW TO USE THE COMPOUND MICROSCOPE TO VIEW SLIDES
Access the Virtual Microscope at…
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Hello,
I need help determining the FOV for the objective microscope, ocular lens please.
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What are microscopes?
Make a brief outline of the history of microscopes?
Relate microscopy with our present status in the scientific and economic world.
What are wet mounts?
How to prepare wet mounts?
How to remove water bubbles in wet mounts?
What are the steps in manipulating / focusing the microscope?
What are the reminders before storing the microscope?
How many times an object is enlarged when
a) HPO is used
LPO is used
Oil immersion objective
a. when to use the coarse adjustment knob?
when to use the fine adjustment knob
if given the chance to manipulate the microscope, what particular specimen would you like to see first . Why ?
Conclusion : state your conclusion
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Drag the images or descriptions to their corresponding class to test your understanding of various types of microscopes and the
images that they produce.
Bright-Field Microscope
Dark-Field Microscope Scanning Electron Microscope
Provides a three-
dimensional image
when a computer
combines multiple
optical sections of a
specimen stained
with fluorescent dye
Common light
microscope used in
the general
microbiology lab
course
Common light
microscope used in
the general
microbiology lab
course
Fluorescent Microscope Phase Contrast Microscope
Confocal Microscope
Provides a three-
dimensional image
when a computer
combines multiple
optical sections of a
specimen stained
with fluorescent dye
A light microscope
that provides brightly
colored, highly
contrasting, three-
dimensional images
of live specimens
A light microscope
that provides brightly
colored, highly
contrasting, three-
dimensional images
of live specimens
Differential Interference Microscope
Transmission Electron Microscope
< Prev…
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Using the microscope Answer the following questions as you work through this exercise:
1. How is the letter “e” on the slide oriented when you see it with the naked eye as you mount it on the stage (i.e., is it right side up or upside down)?
2. How is the letter “e” on the slide oriented when you see it under low or high power magnification?
3. What effect, if any, does the compound light microscope have on the orientation of the image?
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If I also observe something let's say if I was I was 50 nm inside which microscope would you recommend me using?
In the image is that the correct answer to the question
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Can someone answer and explain the following?
What are the basic components of a Fluorescence Microscope and what are the functions of each?
Are there any parts that you can remove without compromising accuracy and utility of the equipment?
Can you suggest additional components to improve the equipment?
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I have a hard time with this picture and I don't know which I put the right label on this picture. Can you help me?
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You are in charge of buying new microscopes for your company, and you have been comparing different types of microscopes. One
important property for microscopy is the resolution, which measures the ability to distinguish two small objects that are close together.
Rank the following list of microscopes from lowest to highest resolution.
Microscope List (5 items)
(Drag and drop into the appropriate area)
Transmission electron
microscope (uses high energy
electron beam)
X-ray microscope (uses x-ray
absorption to image sample,
range 0.01-10 nm)
Confocal fluorescence
microscope (uses a blue laser
as a light source, 488 nm)
Level of Resolution
2
Lowest
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Differences between bright field microscope and inverted microscope
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Fill in table 1 below for the characteristics of your microscopes.
Table 1- Characteristics of the microscope
Low Power
(Dry)
High Power
(Immersion
Oil)
Features
Medium
Power
(Dry)
Focal length (mm)
Working distance (mm)
Linear Magnification (X)
Numerical aperture (N.A.)
Diameter of front lens (mm)
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- True or false? light microscopy has a limit of resolution of 200nm. phase contrast microscopy can be used to observ thick (more than 2 cells)speciments. mammalian cells are grown in a humidified incubator at 30C and 5% CO2.arrow_forwardAs ENRICHMENT CARD THINGS TO REMEMBER: A compound microscope like me, is an instrument used to see organisms or objects that are too small to be seen by the naked eye. Plant and animal cells, different kinds of microorganisms and even mineral samples are microscopic specimens since they are invisible to the eye. A microscope is needed to see them. The microscope magnifies these specimens several hundred times or more. The science of investigating very tiny organisms and small objects using microscope is called microscopy. A compound microscope has magnifying parts that make the specimen look bigger. Lenses, such as the eyepiece or ocular and the objective lenses are the magnifying parts. There are different objective lenses; Low Power Objective (LPO) covers a wide field of view, it usually has a 10X magnification; High Power Objective (HPO) has a magnification of 40X or 43X is ideal for observing very fine detail and it is usually longer than the LPO and oil immersion objective has a…arrow_forward3D dimensionality is a limitation of the compound microscope. Depth of field, DOF, describes dimensionality form top to bottom and can be observed with colored cross threads. Observe the crossed thread slide on low power (4x), then on medium power (10x), then on high power (40x objective magnification). Which crossed fiber is on top? How do you know?arrow_forward
- PART C: CALCULATING THE DIAMETER OF THE FIELD OF VIEW (FOV)_ The field of view (FOV) is the circular area you can see when you look through the microscope. The diameter of the field of view is different depending on which objective lens you are using. For example, you are using the medium-power objective lens, then the area you can see is actually smaller than if you were using the low-power objective lens. Knowing The diameter of the field of view can help you estimate actual size of objects / cells seen through the microscope. When the revolving nose piece is turned to the low power objective lens, a dear plastic ruler can be placed on the microscope stage (see figure 1). Then, the coarse adjustment knob can be used to focus on the millimeter marks of the ruler making sure that one of the milimeter marks is at the left edge of the field of view (see figure 2). NOTE: Slage cip I-1000 Objects in the FOV are usually measured in micrometers (um). To convert, a FOV in mm, times it by 1000…arrow_forwardPlease explain the tablearrow_forwardThe most widely used type of light microscope is the Multiple Choice bright-field microscope. dark-field microscope. phase-contrast microscope. confocal microscope. fluorescence microscope.arrow_forward
- Simulated data: Imagine you collect the following images at the above magnifications. Figure 3-2: Images of cheek cells at the above magnifications. Labelling Drawing: Label only the microscope image taken at 1000x magnification. Add lines and labels (as per guidelines for scientific drawings). You should include: A scale bar showing a unit length of 20 µm. (Hint: The length of the human cheek cell shown is 60 um). Labels for the cell membrane, nucleus, and cytoplasm.arrow_forwardThis is just a labster demonstration not a test, I am having trouble finding the answer in the textarrow_forwardPlease answer fastarrow_forward
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