Preparing An Onion Skin Microscope Slide
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Imagining a cell is sometimes hard for students the first time around. Think about it. A cell is so small that you cannot see it with the naked eye, yet it contains many complex structures that run complex processes all within a permeable cell membrane and they are the building blocks of all life. That is kind of mind-blowing, don’t you think?
When we first introduce cells to students, we start simple with just the basics. We talk about cell membranes, cytoplasm, mitochondria, and nuclei. The students might color cell pictures or build cell models. But, for cells to become reality sometimes we just need to look at them directly. All you need is a microscope and a slide!
I believe that most students from pre-school up should be introduced to microscopes. Kids can be trained to properly operate and care for them. My little man has been using a microscope since he had to climb up on the chair and stand to see into the eyepiece.
Related posts: How To Choose A Homeschool Microscope and How To Use A Microscope With Young Learners
Preparing A Wet-Mount Onion Skin Slide
You could buy prepared slides with various cells already mounted upon them, or you could just make your own. All you need is:
- an onion
- a knife
- tweezers
- water
- eye dropper
- iodine
- a microscope slide
- a cover slip
First, place a small drop of water on a microscope slide. This is to hold the onion skin and to keep it from drying out.
Cut the onion into sections. Take a piece from on of the sections and peel off a small, thin piece of the onion epidermis, or skin. Using tweezers, place the onion skin onto the drop of water on the slide.
Now, drop a small amount of iodine onto the onion skin. The iodine will bind to the starch in the cell wall and nucleus of the onion cells, staining them, and making them easier to see.
Carefully, place the cover slip on top of the stained onion skin. You are now ready to view under the microscope!
Viewing Your Onion Skin Microscope Slide
We are using the Accu-Scope 3088 LED from MicroscopeCentral.com. This is the perfect homeschool microscope. You can read all about it in the post Why Microscopes Make Perfect Christmas Gifts.
One fantastic accessory we love to use is the  AccuCam 3.0 M.P. eyepiece camera from MicroscopeCentral. It fits perfect with our Accu-Scope 3088 microscope. The software that comes with it is easy to use. It allows us to not only see what is on the slide on our computer screen, but to take a screen shot and make enhancements to the image.
The camera allows all of us to look at the specimen under the microscope at the same time. No more fighting over the microscope!