Step 1: Microscope Scale
It is important to know what the scale of your object is. Often times if you draw an
object and do not label the scale others will not know how big your object is. Our
microscopes have 3 different magnifying powers. Generally we call them low,
medium and high. Using the table below calculate the total magnification of each of
the lenses and copy the completed table into your science notebook. Then answer
the following questions.
POWER
Low
Medium
High
EYEPIECE
OBJECTIVE
TOTAL
MAGNIFICATION MAGNIFICATION MAGNIFICATION
10x
4x
40x
10x
400x
Total magnification= eyepiece magnification x objective magnification
Questions
1)
2)
3)
4)
How many eyepieces does your microscope have?
How many objective lenses?
What is the highest magnification your microscope can have?
Where is the objective magnification number found on the microscope?
Step 2: Low and Medium Power Focusing
In order to see your object clearly you need to focus your lenses. Focusing your lens
is very important and can take practice. Please write the following steps in your
journal and then follow each step to focus on the object on the microscope. Once
you have focused in low power draw a picture of what you see in your journal. Then
focus again in medium power and draw a picture of what you see in your journal.
Steps to Focus on Low and Medium Power
1) Turn the coarse adjustment knob so that the stage moves all the way down.
2) Look in the eye piece and roll the knob towards you until you can see the object
and it is in focus.
3) Now use the turn fine adjustment knob to see even more detail by bringing the
object into finer focus.
4) Make observations and draw what you see.
Low Power (40x)
Medium Power (100x)
Step 3: High Power Focusing
High power focusing allows you to see very fine details of the object you are viewing.
Focusing in high power must be done very carefully. It is very important to
remember that you NEVER use the coarse focus knob when using the high power
lens. If you do you can break the microscope lens and the slide. Microscopes are
very expensive so you do not want to do this. Write down the following steps for
focusing in high power in your journal. Then using the following steps use the
microscope to focus on the object and draw a picture in your journal. Remember
DO NOT use the coarse focus knob.
Steps for Focusing in High Power
1) First, follow the directions to bring the object in to focus on low power and then
on medium power.
2) Once the object is in focus on medium power carefully click the high power
objective into place. (Do not force it)
3) Use ONLY the fine adjustment knob to focus on the object.
4) Make observations and draw what you see.
High power (400x)
Step 4: Mounting and Cleaning Slides
Part 1: Mounting Slides
There are two types of slides you will use with a compound microscope, a dry
mounted slide and a wet mounted slide. When mounting each slide you will need
both a rectangular glass slide and a clear slide cover. Please copy down the following
diagrams and then practice mounting the two objects provided using the following
directions.
Dry Object Mounting
+
Glass Slide
+
Small, Thin Object
Slide Cover
Wet Object Mounting
+
Glass Slide
+
Object
+
1-2 drops water
Slide Cover
Now practice mounting the dry mount and wet mount objects. Place the object flat
in the center of the slide. For the wet mount place 1 drop of water onto the object.
For both mount tops place the slide cover on top by placing one side against the
slide at a 45° angle and slowly set the rest of the cover down. This helps avoid air
bubbles from forming under the slide. Then place the slide on the stage for viewing.
DO NOT press down on the slide cover, doing so will damage and possibly kill the
object being viewed.
How to set the slide cover on the slide
Part 2: Cleaning Slides
When cleaning a slide it is very important to not lose the slide covers. Follow the
following directions to clean your slide. Then record these directions in your
notebook using your own words. (You may use a combination of words and pictures
if you like).
1) Carefully remove the slide cover from the slide and rinse lightly in the sink.
2) Place the slide cover on a piece of paper towel so you don’t lose it.
3) Next rinse the slide gently in the sink and dry softly with a towel. You may
need to rub the slide between your thumb and forefinger to remove some of
the specimen.
4) Place the dry slide back in your microscope kit or on the counter designated
by the teacher.
5) Place the dry slide cover in the box designated by the teacher.
Step 5: Moving and Drawing Slides
Viewing an object through a microscope can be confusing. It’s like moving an
object under the document camera or playing Halo with inverted controls, if you
want to see right you move left; to practice find the letter e somewhere on the slide
and draw a picture of it. Try to find several e’s before picking one to draw to
practice moving the slide around. You can draw the e in low or medium power, but
be sure to label which power you use.
Now that you have drawn your e
it is time to measure it. Use the
clear plastic ruler from your
microscope kit for scale. Place
the ruler so that you can see it
when looking through the eye
piece near the e. Once you can
see the ruler draw it in the circle,
be sure to keep the scale accurate
by drawing exactly what you see.
Step 6: Transporting your Microscope
Microscopes are very expensive therefore you need to be very careful when moving
microscopes around. Please read and copy the following directions for moving
around a microscope. After you have copied the directions look at each picture
below and identify what the student is doing wrong and write it in your journal.
Moving Microscopes
1) Always carry the microscope with one hand on the arm and one hand on the
base.
2) Never carry the microscope when there is a slide on the stage, even if it is
clipped in.
3) Unplug the microscope after use.
4) If you are the last person to use the microscope move the stag to its lowest
position and turn the object back to the lowest power.
5) If you are the last person to use the microscope for the day, wrap the cord
neatly around the base, NOT around the lenses and place safely back on the
microscope cart.
A)
B)