TOPIC Microscope AIM How do we use a

TOPIC: Microscope AIM: How do we use a microscope?

Total magnification • Eyepiece lens magnification x objective lens magnification

Total magnification=4 x 10= 40

100 x 400 x

Rules • 1. Carrying microscope = when • 1 hand on arm, other hand under base close to using a microscope body

• 2. DO NOT use coarse adjustment under high power • bc it can break the lens or the slide

• 3. Always start off with low power bc it gives you a greater field of view. LOW HIGH

• 4. Before switching to high power you must: • a. focus your image • b. center your image

• 5. Adjust the diaphragm • (When switching from low to high, amount of light decreases)

• 6. Use LENS PAPER to clean lens

What is • Treating staining? specimen with solutions of different colors • Make cell parts more visible

Unstained cheek cells Stained cheek cells

• Examples: • 1. Lugol’s Iodine • (plant cells)

Onion Cells stained with Lugol’s Iodine

• 2. Methylene blue • (animal cells)

Cheek Cells Unstained Stained

Skin Cells stained with Methylene Blue

Wet • 1. Place a drop of water on the slide mount

• 2. Place object on the slide.

• 3. Slowly lower cover slip onto specimen on an angle to avoid AIR BUBBLES.

• 4. Absorbed excess water with a paper towel.

How do • Upside down & backwards images appear? On the slide Seen through lens F

What • Image moves in happens opposite direction when you move the slide?