Our Microscope

6th Grade Science

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use.

Photo by D. Tresten, 2002

Compoundmicroscope

Eye piece

Body tube

Base

Coarse adjustment knob

Arm

Fine adjustment knob

Revolving nosepiece

Diaphragm

Light source

Stage opening

Stage clips

Stage

Magnify 10 X

Objectivelens

IMPORTANT!Watch How Light Travels Through a

MicroscopeNote: Just study the vertical (up and down) portion of the light

beam! The horizontal (right/left) portion is not in our microscope.

Molecular Expressions Microscopy Primer: Anatomy of the Microscope - Transmitted Light Microscopy Optical Pathways: Interactive Java Tutorial

Which type of lens is in a microscope?

• Convex Lens(Pooches out in the middle!)

• Concave Lens(Caves in in the middle!)

A convex lens is used in the microscope.

In Which Objects would Convex Lenses be Used?

Click to see7 images

In Which Objects might Concave Lenses be Used?

Click to see7 images

Total Magnification -What is it?

To find the total magnification at which a microscope is set, just multiply the power of the eyepiece (10x) times the power of the objective that is in place.

Click to practice finding total magnification…

Magnification: Multiply

If…Eye piece 10 X

Objective Lens 4 x

Total magnification is 40 X

Practice calculating Total Magnification:

If the eye piece is 10 x and the objective lens is 40 x the

magnification is...

If the eye piece is 10 x and the objective lens is 20 x the

magnification is...

If the eye piece is 10 x and the objective lens is 10 x the

magnification is...

400x

200x

100x

Microscopes are not toys!!

They are expensive tools!!

Microscope Rules

1. Always use two handsto carry a microscope!

One hand goes under the baseand one on the arm.

2. Do not touch the lenses. If they are dirty, only clean with special lens paper.

3.Be cautious when handling glass slides. Notify teacher if a slide breaks.

(Students should not handle broken glass.)

4. Always keep the scope away from the _______ of the_________.

Care of the MicroscopePage 3 of 3

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How to Use the Microscope

1. STAGE down! (away from objectives)

2. Plug in the microscope.3. Twist 4x (Low-Power) OBJECTIVE until it

clicks into place! (using nosepiece NOT objectives)

4. Stage CLIPS out!5. SLIDE on6. Stage CLIPS back in (carefully placed on top

of slide)

7. Switch on LAMP

Before using the Scope, Wake It Up:

Use of the MicroscopePage 1

1. Make sure that the

stage is all the way

DOWN and slide

is in place.

Down

In place

2. Set Scope to Low Power (4x)

In other words, set the 4x objective in place over the stage opening.

4x Objective

3. Turn the coarse adjustment knob to raise the stageto focus the slide.

4. Next, turn the fine adjustment knob until the specimenis in sharp,clearfocus.

Use of the MicroscopePage 3

5. If there is too little light, rotate the disc diaphragm to another opening.

How to Focus on a Specimen, Cont’d:

Close-up of disc diaphragm(as seen from underneaththe stage)

Do you see the largest hole that lets the most light pass? Which hole transmits the least light?

What is this?

“Field of Vision” in a Microscope

Pointer in eyepiece

Always put our microscopes “to bed” after labs:

Use of the MicroscopePage 4

1. Lamp off

2. Unplug

3. Stage down (Away from objectives)

4. All slides are removed

5. Clips IN

6. Clean stage

7. Dust cover ON

8. Put all slides and other materials in proper places

Wet Mount with a Squashed Air Bubble in It

How to Add More Water to a Wet Mount without

Starting All Over Again!

Why Learn to Use a Microscope?

To see cool things like anything on the following

web page!

http://www.molecularexpressions.com/moviegallery/pondscum.html

Magnify 10x

Support / Hold lenses in place

Support microscope

Focus quickly but imperfectly (coarsely)

Hold body tube/Carry

Focus very slowly more perfectly (actually moves the stage away from/toward the objectives)

To turn objectives (lenses) into place

over specimenTo magnify 40x

Allow more/less light

Send light up through specimen

Allow light to reach specimen / Catch spilledmatter

To magnify about 10X

Hold slide

To magnify about 4X