Microscopes

Microscopes

Parts of a Compound Light Microscope

• Objective lenses: These lenses magnify the specimen.

• Eyepiece: Also known as the ocular lens, it further magnifies the image.

• Stage: The platform where the specimen is placed.

• Condenser: Focuses light onto the specimen.

• Light source: Provides illumination for the specimen.

• Diaphragm: Controls the amount of light on the specimen.

​Microscope Parts

• ​Ocular Lens

• ​Stage

• ​Objective Lenses

• ​Diaphragm

• ​Coarse Adjustment Knob

• ​Fine Adjustment Knob

• ​Light

​Parts of a Microscope

1. ​Objective Lens = Lens closest to the specimen; directs light to the ocular.

2. ​Ocular = Eyepiece; Lens in eye piece

3. ​Revolving Nosepiece = Holds the objective lenses; allows for adjustment of objective lenses to higher or lower magnification.

​Parts of a Microscope

​4. Stage = holds the specimen to be viewed

​5. Stage Clips = keeps the microscope slide in place

​6. Diaphragm = adjusts the amount of light that passes through the specimen

​7. Light source = source of light on the microscope

​8. Arm = holds the ocular and revolving nosepiece; carry using the arm

​Parts of a Microscope

​9. Coarse Adjustment knob = allows for focus of the specimen at low magnification; only use on low magnification

​10. Fine adjustment knob = used to focus specimen at high magnification

​11. Base = the bottom of the microscope; put one hand under the base to carry

Microscope Illumination

Did you know that the diaphragm is responsible for regulating the amount of illumination to the specimen in a microscope? The condenser focuses and directs light onto the specimen, enhancing visibility. The diaphragm then allows a portion of that light to pass through. Without the condenser and diaphragm working together, observing microscopic details would be challenging.

Controlling Light with Diaphragm

The diaphragm is a mechanism in microscopes that controls the amount of light passing through the specimen. By adjusting the diaphragm, you can increase or decrease the brightness of the image. Use the diaphragm to optimize the lighting conditions for better visibility and contrast.

• Open the diaphragm for more light

• Close the diaphragm for less light

In figure (a) the diaphragm is 100% open allowing the most light through.

100% Open

In figure (b) the diaphragm is 80% open creating a less bright image.

80% Open

40% Open

In figure (c) the diaphragm is 40% open. This image is quite dark.

Multiple Choice

What part of the microscope determines the amount of light on the specimen?

• Objective lenses

• Eyepiece

• Diaphragm

• Condenser

Dropdown

​ Clarence wants to observe his specimen under the microscope but it is too dark to see any details. In order to better view his slide what does Clarence need to do?​

Select answer

Objective Lenses

• Objective lenses are used in microscopes to magnify the specimen.

• They are available in different magnification powers, such as 4x, 10x, 40x and 100x.

• Higher magnification lenses provide more detailed views of the specimen.

• Objective lenses are typically color-coded for easy identification.

​The paramecium in the 40x view are magnified by the low power lens (4x) and the eyepiece (10x). They appear 40 times bigger!

4 x 10= 40

40x

The paramecium in the 100x view are magnified by the medium power lens (10x) and the eyepiece (10x). They appear 100 times bigger!

10 x 10= 100

100x

The paramecium in the 400x view are magnified by the high power lens (40x) and the eyepiece (10x). They appear 400 times bigger!

40 x 10= 400

​​400x

Multiple Choice

What is the purpose of objective lenses in microscopes?

• To magnify the specimen

• To illuminate the specimen

• To rotate the specimen

• To clean the specimen

Match

Match the lens to its magnification power.

• Low Power Lens

  (Red)

• Medium Power Lens (Yellow)

• High Power Lens

  (Blue)

• Ocular Lens

• Highest Power Lens (White)

10x
(Objective Lens)

20x

40x

10x

(Eyepiece)

100x

• 10x
  (Objective Lens)

• 20x

• 40x

• 10x

  (Eyepiece)

• 100x

Multiple Choice

What does the diaphragm control in microscopes?

• Amount of light passing through the specimen

• Magnification of the image

• Color of the specimen

• Size of the specimen

Use headphones if needed!

On the next slide you're going to watch a video about how to focus a microscope!

​Our microscopes are slightly different but that is OK! Observe how the scientist knows she is in focus!

Coarse Adjustment

• Coarse adjustment is used to roughly focus the microscope on the specimen.

• It is done by moving the stage up and down using the coarse adjustment knob.

• Be careful not to crash the objective lens into the slide as it may damage both.

Multiple Choice

What is coarse adjustment used for in a microscope?

• To roughly focus the microscope on the specimen

• To fine-tune the focus of the microscope

• To adjust the lighting of the microscope

• To clean the lenses of the microscope

Fine Adjustment

• The fine adjustment knob is used to fine tune your image.

• Typically, the fine adjustment knob will only be used in medium and high power magnification, as it moves the stage very slightly.

Multiple Choice

What is a fine adjustment knob used for in a microscope?

• To roughly focus the microscope on the specimen

• To fine-tune the focus of the microscope

• To adjust the lighting of the microscope

• To clean the lenses of the microscope

Steps for Focusing a Microscope

Step 1. Turn on your microscope and check that it is on the lowest power.
Step 2. Place the slide centered over the condenser on the stage, so that light shines through it and clip it in place.
Step 3. Slowly turn the coarse adjustment knob while looking through the eyepiece until your specimen comes into focus.
Step 4. Turn the fine adjustment knob and diaphragm to adjust the image.

Drag and Drop

What are the correct steps for focusing your microscope?

Step 1. ​

Placeholder

Step 2. ​ ​

Placeholder

Step 3. ​

Placeholder

Step 4. ​

Placeholder

Step 5. ​

Placeholder

Drag these tiles and drop them in the correct blank above

Turn on your microscope

Check that your microscope is on low power.

Place your slide above the light source.

Slowly turn the coarse knob to find the specimen.

Adjust with the diaphragm and fine adjustment

​Warning!!!

Carrying a Microscope

Hold the microscope by the arm and support it under the base

Multiple Choice

Which image shows the correct way to carry a microscope?

• A

• B

Multiple Choice

The first direction to move the stage using the coarse focus before putting the slide on the stage.

• up

• down

Multiple Choice

After putting the slide on the stage, when should coarse focus be used?

• only in high power

• only in low power

Multiple Choice

When should the fine focus be used?

• Only after using coarse focus

• on low power before using coarse focus

Multiple Choice

What objective lens should you start with?

• low power

• high power

Multiple Choice

What goes on top of the specimen (the thing you want to look at)?

• the slide

• the coverslip

Multiple Choice

Slides are glass, what do you do if they break?

• pick up the pieces with your hands

• it's glass, tell your teacher!

Multiple Choice

Coverslips are big and hard to lose.

• true

• false

Multiple Choice

When moving the stage, you have to be careful not to __________.

• break the slide

• move it to far down

• break the lightbulb

Multiple Choice

When you clean the lens what should you use?

• lens paper

• tissues

Now it is time to practice your microscope knowledge!

Good Work!

Hotspot

Where are the objective lenses?

Hotspot

Where is the stage?

Hotspot

Where is the coarse adjustment knob?

Hotspot

Which part is used to focus the microscope on low power?

Hotspot

Which part is used to magnify and view the object?

Hotspot

Which part is used to focus for fine details?

Hotspot

Where is the specimen placed?

Multiple Choice

Which knob is used first to focus the specimen on low power?

• fine adjustment knob

• eyepiece

• coarse adjustment knob

• objective lens

Multiple Choice

Why is it important to carry the microscope with two hands?

• so you will not drop it

• so the microscope does not turn over

• it is not important to carry it with two hands

Multiple Choice

If the eyepiece is magnified 10x and the objective lens is magnified 40x, what is the total magnification?

• 40x

• 50x

• 400x

• 10x

Reorder

Place the steps to focusing the microscope in the correct order from start to finish.

• use the

  coarse adjustment knob to focus on low

• change the objective lens to medium power

• use the fine adjustment knob to focus on medium

• change the objective lens to high power

• use the fine adjustment knob to focus on high power

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Fill in the Blanks

Fill in the Blanks

Fill in the Blanks

Drag and Drop

To carry a microscope, place one hand on the ​

Placeholder

and one hand under the ​

Placeholder

.

Drag these tiles and drop them in the correct blank above

arm

base

stage

body tube

diaphragm

Drag and Drop

There are three lenses attached to the revolving ​

Placeholder

. The shortest (colored red) is the ​

Placeholder

objective, the yellow lens is the ​

Placeholder

objective, and the longest lens (colored blue) is the ​

Placeholder

objective.

Drag these tiles and drop them in the correct blank above

nosepiece

low

medium

high

Drag and Drop

The microscope should always start on the ​

Placeholder

power so you don't ​

Placeholder

anything. Adjust the ​

Placeholder

all the way ​

Placeholder

, then place your specimen (your slide) on the stage under the ​

Placeholder

.

Drag these tiles and drop them in the correct blank above

low

break

down

slide clips

stage

Drag and Drop

Always adjust the focus with the ​

Placeholder

focus knob first. After you can see the object, make your final adjustments with the ​

Placeholder

focus knob. If it is too dark, turn the dial on the ​

Placeholder

to make the light brighter.

Drag these tiles and drop them in the correct blank above

coarse

fine

diaphragm

Multiple Choice

How do you adjust the amount of light shining through your microscope?

• Turn the coarse focus knob on the side of the microscope

• Spin the eye piece around to a new position

• Change the objective lenses to a different color

• Turn the fine focus knob on the side of the microscope

• Rotate the diaphragm, the large, black, flat dial built into the stage

Drag and Drop

After your object is in ​

Placeholder

, you may now use the ​yellow

Placeholder

and​ blue

Placeholder

powered objective lenses.

Drag these tiles and drop them in the correct blank above

focus

medium

high

Drag and Drop

NEVER use the large ​

Placeholder

focus knob when on the blue high power!!!



You can hit the slide and ​

Placeholder

the slide AND / OR the lens!!!

Drag these tiles and drop them in the correct blank above

break

coarse

fine

Match

If you put the graph paper on your microscope, and focused it on the low (red), medium (yellow), and high (blue) powers.

What would the graphing paper looked like under each power of the microscope?

Low Power

(Red)

High Power

(Blue)

Medium Power

(Yellow)

• Low Power

  (Red)

• High Power

  (Blue)

• Medium Power

  (Yellow)

Multiple Choice

What happened to your field of view as you moved from low to high power?

• The view increased -

  I could see more of the slide

• The view decreased -

  I could see less of the slide

• The amount of slide I could see stayed the same

Multiple Choice

Set your microscope to the low power (red lens).

When you move the slide to the left, in what direction does the letter “e” appear to move?

• Forwards

• Backwards

• To the Left

• To the Right

Multiple Choice

Set your microscope to the low power (red lens).

How does the “e” move when you move the slide to the right?

• Forwards

• Backwards

• To the Left

• To the Right

Multiple Choice

Set your microscope to the low power (red lens).

How does the “e” move when you move the slide up?

• Down

• Up

• To the right

• To the left

Multiple Choice

Set your microscope to the low power (red lens).

How does the “e” move when you move the slide down?

• Up

• Down

• To the right

• To the left

Match

Set your microscope to the low power (red lens), then the medium (yellow) power, and finally the high (blue) power.

Show what the letter E looked like at different scales.

Medium Power

(yellow)

Just my eyes

Low Power

(red)

High Power

(blue)

• Medium Power

  (yellow)

• Just my eyes

• Low Power

  (red)

• High Power

  (blue)

Multiple Select

Read the attached passage:

Why does a specimen placed under the microscope have to be thin?

Check all that apply.

• So we are able to see clear details in the image

• So that the light can shine through the object

• There are no microscopes that can look at thick objects

• Thick objects are too heavy to put under a microscope

Labelling

Label all the parts of the microscope

Drag labels to their correct position on the image

base

Light

Diaphragm

Objective Lens

Rotating Nosepiece

Eye Piece

Fine Focus Knob

Coarse Focus Knob

Stage

Arm

Labelling

Practice labeling the compound light microscope

Drag labels to their correct position on the image

Fine focus

Clip

Base

Light

Stage

Coarse focus

Tube

Eyepiece

Objective lens

Arm

Multiple Choice

Part B

• Moves the stage very faster for general focus

• Moves the stage slowly for a clear image

Multiple Choice

Part A

• Moves the stage faster for general focus

• Moves the stage slowly for clear image

Labelling

Orderly arrange how the compound light microscope can be used effectively in viewing a specimen on a slide.

Drag labels to their correct position on the image

Turn from 4X to 10X & 40X, and fine tune

Use fine focus for clear image

Use 4X objective first

Hold specimen on stage with clips

Use Coarse focus for general focus

Drag and Drop

​ Eyepiece ( ​

Placeholder

) × Objective lens ( 40X ) = Total Magnification ( 400X )

Drag these tiles and drop them in the correct blank above

10X

4X

40X

100X

Multiple Choice

Total Magnification is

• Objective lens X Eyepiece lens

• Eyepiece lens X Eyepiece lens

• Eyepiece lens X Total Magnification.

Multiple Choice

What is Part 12

• Fine Adjustment Knob

• Coarse Adjustment Knob

• Diaphragm

• Objective

Multiple Choice

What is Part 13

• Fine Adjustment Knob

• Course Adjustment Knob

• Stage

• Diaphragm

Multiple Choice

What is Part 7

• Stage

• Stage Clips

• Light Source

• Diaphragm

Multiple Choice

Regulates the amount of light on the specimen

• Diaphragm

• Stage

• Ocular Lens

• Objective Lenses

Multiple Choice

Field of view is......

• The size of the specimen

• The size of the slide

• The area you can see under the microscope

• The area from which your specimen came

Multiple Choice

As you move from low power to high power, the field of view becomes

• Darker and larger

• Darker and smaller

• Brighter and larger

• Brighter and small

Multiple Choice

The largest field of view shown is under the total magnification _____X.

• 40

• 100

• 400

Multiple Choice

If you wanted to center the image what direction would you move your slide in?

• Down and left

• Down and right

• Up and left

• Up and right

Multiple Choice

Which part of the microscope do you never use under high power?

• Diaphragm

• Coarse adjustment

• Stage

• Fine adjustment

Multiple Choice

Which part of the microscope should you use to focus the image?

• Diaphragm

• Coarse adjustment

• Stage

• Fine adjustment

Multiple Choice

What will be the total magnification if the ocular lens is 10X and the objective lens is 40X?

• 40X

• 10X

• 100X

• 400X

Multiple Choice

If the total magnification is 100x and the objective is 10x, what is the ocular?

• 90x

• 10x

• 110x

• 1000x

Multiple Choice

You can find total magnification by which of the following methods?

• ocular PLUS objective

• ocular TIMES objective

• ocular MINUS objective

• ocular DIVIDED BY objective

Multiple Choice

If you look at a letter such as "e" under the microscope, then how does it look when you are viewing the image?

• upside down and backward

• upside down and distorted

• upside down and front view

Multiple Choice

When making a wet mount, place the coverslip at a 45-degree angle to reduce air bubbles.

• True

• False

Multiple Choice

This picture shows that the microscope:

• only flips images upside down

• only flips images over backwards

• flips the image upside down and backwards

• doesn't flip the image at all

Multiple Choice

The best way to avoid air bubbles when making a wet mount slide is to:

• drop the cover slip on at an angle

• drop the cover slip on flat

• squeeze the slide and cover slip after it is on

• tap on the cover slip once it is in place

Multiple Choice

1.   Describe the purpose of staining cells before viewing them with a microscope

• To clean them

• So they absorb the liquid and grow

• So the parts of the cells can be seen

• So they shrink making them easier to look at

Multiple Choice

Which laboratory procedure is represented in the diagram below?

• placing a coverslip over a specimen

• removing a coverslip from a slide

• adding stain to a slide without removing the coverslip

• reducing the size of air bubbles under a cover- slip

Multiple Choice

Which laboratory technique is shown in the diagram?

• testing a specimen for amino acids

• determining the pH of a specimen

• measuring the photosynthetic rate in a specimen

• preparing a wet mount slide of a specimen

Multiple Choice

The ________ of the microscope would show you the SMALLEST field of view.

• low power objective
• medium power objective
• high power objective
• ocular

Multiple Choice

When looking at a specimen on your slide, you should always start with the

• low objective lens
• medium objective lens
• high objective lens
• super extra high power lens

Multiple Choice

The__________ sharpens the image under high magnification.

• the diaphragm
• fine adjustment knob
• coarse adjustment knob
• the ocular

Multiple Choice

The ________ of the microscope would show you the MOST zoomed in image, or the SMALLEST field of view.

• low power objective
• medium power objective
• high power objective
• stage

Multiple Choice

What power do you start with when using a microscope?

• High power
• Medium power
• Low power
• Extra high power

Multiple Choice

What is the function of stage clips?

• To move the objectives
• To keep the slide secure
• To adjust the focus
• To look through

Multiple Choice

The diaphragm helps to

• focus
• allow light to pass through the stage
• change the lens size

Multiple Choice

A compound light microscope will use _______ or more lenses at the same time.

• 1
• 2
• 3

Multiple Choice

What does a microscope do?

• Produces a magnified (bigger) image of something too small for the eye to see

• Helps us look at stars

• Produces a smaller image of something too big to see at once

• Helps us look at our teeth

Multiple Choice

The greater the ___________________, the smaller the field you are actually viewing.

• detail

• objective

• magnification

• body

Multiple Choice

Which part is #8?

• Revolving nosepiece

• Objective lens

• Stage clips

• body tube

Multiple Choice

What part is # 9?

• Body tube

• base

• arm

• stage

Multiple Choice

What part is #1?

• Base

• Mirror

• stage

• stage clips

Multiple Choice

What part is AB?

• Stage

• Diaphragm

• Light Source

• base

Multiple Choice

What part is E?

• Diaphragm

• Eyepiece

• base

• Light source

Multiple Choice

Which part is D?

• Body tube

• fine adjustment knob

• coarse adjustment knob

• stage

Multiple Choice

Which part is C?

• Stage

• Fine Adjustment knob

• Coarse Adjustment Knob

• diaphragm

Multiple Choice

Which part is B?

• body tube

• eyepiece

• objective lens

• diaphragm

Multiple Choice

Which part is A?

• body tube

• eyepiece

• objective lens

• stage clip

Multiple Choice

Piece 7

• Ocular Lens
• Objective Lens
• Base
• Arm

Multiple Choice

Number 3

• Ocular Lens
• Objective Lens
• Diaphragm
• Base

Multiple Choice

Number 8

• Base
• Stage
• Tube
• Arm

Multiple Choice

Number 10

• Stage
• Stage Clips
• Diaphragm
• Base

Multiple Choice

Number 12

• Course Adjustment
• Fine Adjustment
• Small Adjuster
• Large Adjuster

Multiple Choice

Number 5

• Knob
• Ocular Lens
• Diaphragm
• Objective Lens

Multiple Choice

To focus a specimen, it is best to start with which objective:

• high power

• low power

• scanning

• ocular

Multiple Choice

If you move the slide left while viewing, in which direction will it appear to move?

• right 
• left
• up 
• down

Multiple Choice

A microscope is an instrument that.

• makes faraway objects look closer.
• makes small objects appear larger.
• decreases the size of small objects.
• increases the size of small objects.