AIM: HOW DO WE USE MICROSCOPES? TOPIC: MICRSCOPES AIM: HOW DO WE USE MICROSCOPES? DO NOW: 1.Hypothesize……. What are these pictures of? 2. List safety rules needed in order to work with scopes in the lab.

1.)

2. 3.

1. Carrying microscope always use one hand on arm and the other hand under base close to your body Things to remember when using a microscope

2. DO NOT use the coarse adjustment under high power

3. Always start off with low power b/c it gives you a greater field of view.

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

5. When cleaning a lens, use LENS PAPER 5. When cleaning a lens, use LENS PAPER. Do not use a napkin, or paper towel…

Unstained cheek cells Stained cheek cells

Total magnification Mathematical calculation that tells you how much larger the specimen is than its actual size Formula : Total magnification = Eyepiece X Objective lens

Total magnification=4 x10= 40

100x 400x

Total Magnification: Ocular X Objective = Total (Eyepiece) magnification Practice: Eyepiece Objective lens Total magnification 20x 4x 25x 10x 15x 40x

F Image Appearance Enlarged Upside down & backwards On the slide Seen with naked eye Seen through lens F

1. Place a drop of water on the slide Aim: How do I prepare a Wet Mount Do Now: Identify 4 parts of scope

2. Place specimen on the water using tweezers.

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

Treating a specimen with solutions of different colors to make cell parts more visible Staining

3. Excess water should be absorbed with a paper towel.

Examples: 1. Lugol’s Iodine Used for plant cells

Onion Cells stained with Lugol’s Iodine

2. Methylene blue Used for animal cells

Skin Cells stained with Methylene Blue

Total Magnification: Ocular X Objective = Total (Eyepiece) magnification Practice: Eyepiece Objective lens Total magnification 10x 4x 15x 60x