1. Slide Preparation L/O - To be able to prepare a microscope slide
D. Crowley, 2007

2. Microscope Crossword
Have a go at the microscope crossword - you have five minutes…
Down: -
Lens that you look down
What the slide is placed on
A wheel to make the image clear
Across: -
Lens closest to the slide
The specimen is placed on this
You need this to see something
Eyepiece
Stage
Focusing
Objective
Slide
Light

3. Microscopes Set up a microscope to view an
animal cell - remember the steps to take
Place the smallest objective lens (the smallest lens) over the hole in the stage
Turn the coarse focusing wheel to make the gap between the stage and the objective lens as small as possible
Place a slide on the stage, and secure with the clips
Adjust the light source so light goes up through the stage
Turn the coarse focusing wheel slowing, until your specimen is in focus
To see your specimen in more detail, turn the next largest objective lens over your specimen
Use the fine focusing wheel to get your image into focus again - do not use the coarse focusing wheel - this can break your slide!

4. Preparing Specimens
A specimen is the object we look at under a microscope
The specimen needs to be thin, so light can pass through it
We use a coverslip between the slide and specimen which helps flatten it out. It also helps keep the specimen in place, and stops it drying out
When you have prepared your specimen you can look at it under the microscope. It is vital you know what magnification you are using: this is easy to work out - it is the eyepiece lens x the objective lens:
Magnification = magnification eyepiece lens x magnification objective lens

5. Place your onion skin onto the water droplet on your slide
Preparing Onions
You are going to prepare a slide containing a specimen of onion cells
Follow the slide preparation steps, then draw what you see (using A4 plain paper and in pencil). Also write down your magnification
Magnification = magnification eyepiece lens x magnification objective lens
Place a drop of water on the centre of a slide (this may contain a stain to make the specimen more clear, e.g. iodine)
Cut some onion, then using forceps, peel off the inside layer of a piece of onion
Using a mounted needle, lower a coverslip onto the onion skin. Do this slowly and carefully, to avoid trapping air bubbles!
Place your onion skin onto the water droplet on your slide

6. Magnification
When you have prepared your specimen you can look at it under the microscope. It is vital you know what magnification you are using: this is easy to work out - it is the eyepiece lens x the objective lens:
Magnification = magnification eyepiece lens x magnification objective lens
E.g.
eyepiece lens = 10x
objective lens = 60x Magnification = 10 x 60
= 600x magnification

7. Marking your drawings Level 3 Level 4 Level 5
Prepare a slide with help
Focus the image with help
Indentify parts of the microscope
Draw what they can see
Identify parts of cell with help
Level 4
Identify most parts of microscope and state their job
Draw simple diagram of cell seen under microscope
Identify nucleus and cell wall
Level 5
Prepare slide safely, with only a little help
Focus microscope with only a little help
Name most parts of microscope and describe how they work
Draw an accurate diagram of cells under the microscope
Identify and label parts of cell correctly

8. Marking your drawings Level 5 Level 6 Level 7
Prepare slide safely, with only a little help
Focus microscope with only a little help
Name most parts of microscope and describe how they work
Draw an accurate diagram of cells under the microscope
Identify and label parts of cell correctly
Level 6
Prepare a slide safely without help
Focus the image at low and high magnification
Identify all parts of microscope and describe how they work
Draw an accurate diagram of cell seen under microscope
Make a reasonable estimate of the size of the cell
Level 7
Prepare a slide safely and competently without help
Focus the image at all 3 magnifications
Explain in detail how the microscope works
Identify and label parts of cell correctly, identifying problems
Make a accurate measurement of the size of the cell