De microscoop

• Biologie
• Middelbare school
• vmbo k, g, t, mavo, havo, vwo
• Leerjaar 1

Biology

the microscope

aims of this lesson

at the end of the lesson:

You know what a microscope is

you know the names of the parts of a microscope

You know the function of these parts

You know how to use a microscope 

you practiced in how to use a microscope

Watch out!!

If you can't see an object or a part of the object with the naked eye you can use a mignification glass or a microscope. 

Onderdelen 

1. eyepiece ( ocular lens)

2. arm

3. base

4.  light source

5. small adjustment knob

6. coarse adjustment knob 

7. diaphragm

8. stage

9. stage clips

10. objective lenses

11. revolving nosepiece

Microscope 

At school we can::

40 x magnify,

100 x magnify or 

400 x magnify. 

objective lensen x

ocular lens

Calculate maginification

vergroting oculair x vergroting objectief = totale vergroting

example:

ocular magnifies  10 x and the objective 40 x. 

the magnification is 10x 40 x = 400 x 

next video start at 3.28

What is the function of the diaphragm of the microscop?

1. to magnify
2. to regulate the light
3. to hold the microscope
4. to swith microscope on/off

How do you mak a sharp image of your slide?

Through which part of the microscope do you look when looking at al slide

1. diaphragm
2. objective lens
3. ocular lens
4. revolving nosepiece

What is the function of the objective lensen?

1. magnify the slide
2. regulate the amount of light
3. create sharp image
4. to hold you microscope

Instructions

1. When moving your microscope, always carry it with both hands (Figure 1, at left). Grasp the arm with one hand and place the other hand under the base for support.

2. Turn the revolving nosepiece so that the lowest power objective lens is "clicked" into position (This is also the shortest objective lens).

Instructions

3. Your microscope slide should be prepared by placing a coverslip or cover glass over the specimen. This will help protect the objective lenses if they touch the slide. Place the microscope slide on the stage and fasten it with the stage clips. You can push down on the back end of the stage clip to open it.

Instructions

4. Look at the objective lens and the stage from the side (Figure 2, at right) and turn the coarse focus knob so that the objective lens moves downward (or the stage, if it moves, goes upward). Move it as far as it will go without touching the slide!

Instructions

5. Now, look through the eyepiece and adjust the illuminator (or mirror) and diaphragm (Figure 3,Microscope Viewingat left) for the greatest 

Instructions

6. Slowly turn the coarse adjustment so that the objective lens goes up (away from the slide). Continue until the image comes into focus. Use the fine adjustment, if available, for fine focusing. If you have a microscope with a moving stage, then turn the coarse knob so the stage moves downward or away from the objective lens.

Instructions

7. Move the microscope slide around so that the image is in the center of the field of view and readjust the mirror, illuminator or diaphragm for the clearest image.

8. Now, you should be able to change to the next objective lens with only minimal use of the focusing adjustment. Use the fine adjustment, if available. If you cannot focus on your specimen, repeat steps 4 through 7 with the higher power objective lens in place. Do not allow the objective lens to touch the slide!

Instructions

9. The proper way to use a monocular microscope is to look through the eyepiece with one eye and keep the other eye open (this helps avoid eye strain). If you have to close one eye when looking into the microscope, it's ok. Remember, everything is upside down and backwards. When you move the slide to the right, the image goes to the left!

Instructions

10. Do not touch the glass part of the lenses with your fingers. Use only special lens paper to clean the lenses.

11. When finished, raise the tube (or lower the stage), click the low power lens into position and remove the slide.

Practical

1. Look at the letter e from a newspaper.

Use maginfiation 40x

How does this letter look like? 

Make a drawing of this letter in your notebook

Practical

2. Take a hair from you and your partner

Put it on a slide with sticky tape in an x- shape (so they are crossed)

look at it with a magnification of 100x

Finish

remove the slide from your microscope 

hand in your microscope and clean your desk

Did you lik it?

study well for the SO