T. Trimpe 2005

http://sciencespot.net/

Body Tube

Nosepiece

Objectives

Stage Clips

Light

Ocular lens

(Eyepiece)

Arm

Stage

Coarse Adjustment

Fine Adjustment

Always carry a microscope with one hand

holding the arm and one hand under the base.

Base

Diaphragm

What’s my power?

To calculate the power of magnification, multiply the power of the

ocular lens by the power of the objective.

What are the powers of

magnification for each of

the objectives we have on

our microscopes?

Fill in the table on

your worksheet.

Lab Expectations

• Treat the microscope with respect, it is an

expensive piece of scientific equipment.

• If you are unsure of how to do something,

ask! Do not “force” the microscope lenses

into position.

• Look at the chart, what needs to be filled in?

• What is the best way to approach this task?

Comparing Powers of Magnification

We can see better details with higher the

powers of magnification, but we cannot see

as much of the image.

Which of these images

would be viewed at a

higher power of

magnification?

What happens to our

view of an image as you

increase the power or

magnification? (Hint: 2

things)

Lab Expectations

• Treat the microscope with respect, it is an

expensive piece of scientific equipment.

• If you are unsure of how to do something,

ask! Do not “force” the microscope lenses

into position.

• You will be working with glass – breaking

hazard!

• If at any point you are not following lab

expectations, you will be asked to stop the

lab.

Lenses • What is different about the length of each

lens?

• So, why can’t you use the largest objective

for some slides?

Be careful with the largest objective! Sometimes there is

not enough room and you will not be able to use it!

How to use a microscope

1 – Turn on the microscope and then rotate the nosepiece to click the

red-banded objective into place.

2 – Place a slide on the stage and secure it using the stage clips. Use

the coarse adjustment knob (large knob) to get it the image into view

and then use the fine adjustment knob (small knob) to make it

clearer.

4 – When you are done, turn off the microscope.

3 – Once you have the image in view, rotate the nosepiece to view it

under different powers. Draw what you see on your worksheet!

Be careful with the largest objective! Sometimes there is

not enough room and you will not be able to use it!

How to make a wet-mount slide …

1 – Get a clean slide and coverslip from your teacher.

2 – Place ONE drop of water in the middle of the slide. Don’t use

too much or the water will run off the edge and make a mess!

3 – Place the edge of the cover slip on one side of the water drop.

You do not need to use the stage clips

when viewing wet-mount slides!

5 – Place the slide on the stage and view it first with the red-banded

objective. Once you see the image, you can rotate the nosepiece to

view the slide with the different objectives.

4 - Slowly lower the cover slip on top of the drop.

Cover

Slip Lower slowly

What you might find:

Metapus Paramecium

Amoeba Didinium

Pond Water Procedures and Clean Up

1. Get a slide and cover sheet from me.

2. Pick up the sample of pond water (in a small cup) and a

dropper.

3. One person will make the slide, and the others in the

group will view that same slide once it is made.

4. Follow the instructions on your page.

5. Another person in the group will clean off the slide

(carefully – it is glass) and the cover sheet.

6. I will have a place on the front lab table to place these.

7. Place the prepared amoeba slide back on the stage, under

the clips – CAREFULLY!

After:

Before:

http://videoserver.magnet.fsu.edu/micro/pondscum/protozo

a/amoeba/mpeg/amoeba01df40x.mpg

Amoeba Video: