Mircoscopy

Equipment

• light mircoscope

• mircoscope slide

• cover slip

• white tile

• iodine solution

• onion

• forceps

• white tile

• scalpel

Method

1. peel off epidermal layer using forceps

2. put on mircoscope slide with drop of watter using a pipette using tissue lies flat

3. add 2 drops of iodine solution to stain cells

4. place down slowly a cover slip at a 45 degreee angle to the onion with one side touching the onion in order to prevent air bubles from being trapped and affect its view in the mircoscope

5. clip the slide carefully onto the stage

6. ensure the lowest-powered objective lens is over the slide

7. use the coarse adjustment knob to bring the stage up just below the lens

8. look down the eyepiece and gradually move the stage downwards using the coarse adjustment knob; stop when the image is roughly in focus

9. bring the image into focus by adjusting the fine-adjustment knob until a clear image is obtained (the focusing knobs make the image sharper; they do not change the magnification, so don't describe them as "zoom")

10. observe the image with a higher magnification, by changing the objective lens to a higher power and readjust the stage using the coarse and fine adjustment knobs

Safety

sharp knife or scalpel may cut you, so cut on a chopping board, away from your body, keeping fingers away from the blade

Wear goggles or gloves when handling iodine as it can irrtate the skin

Aim

investigate a seleceton of plant or animal cell using a light mircoscope

Sources of error and fixes

Trapped air bubbles blocking mircoscope view

Lower the coverslip gently at a 45-degree angle using a mounted needle