Growing Bacteria Science Project

Why can’t you scrape some saliva out of your mouth, put it on a clean plate, place a lamp over it, put it in a dark room, wait a few days, come back, and have a completed science project called Grown Bacteria?

Well, you could, of course, but it wouldn’t fly too far. How far, you might ask. About as far as the waste basket, or toilet, I’d answer.

Do you know why?

Let’s list the reasons, one by one.

There are too many variables. That’s right. Unfortunately, the human mouth is absolutely chock full of germ culture. Also, there might be a bacteria or two stowed away on the plate. Then, there’s that lamp. How hot is it going to get? And, three days. Exactly? Oh yeah, the air has germs in it too. Plus your toothpick. Where was it before it landed in your mouth, and afterwards? Well, too many variables is only one reason why it all went wrong, really. Let’s try again.

You’ll need the following equipment.

(Try to match which correct object matches the wrong one….)

*Petri dish

*Agar . You could make your own by taking some gelatin (unflavored jello). No? Beef bouillon and sugar. Why not gelatin or why? True agar is available at Asian food stores, by the way.

Are you keeping notes?

Anyway, whatever it’s made of, it’s still likely to end up looking ghastly. Why? Because the solution will get contaminated.

If you’ve been following these science projects, you’ll remember that we killed bread mold by keeping bread in an ultraviolet bread box. That is exactly what you’ll need to use here, too. Put the petri dish under a UV light for a few minutes. While you’re at it, kill any germs on the swab.

Whoops. We forgot to wipe off the bench or counter with a disinfectant or rubbing alcohol.

Now, instead of three days in a dark room, let’s just use a Bunsen burner, or one of those propane flame burners.

Look around you. Move the whole apparatus if you’re close to ventilation ducts that could bring their own germs or dust to the party.

Arch Rule 1.Sterile, sterile. sterile. You. Your hands. Your mouth, your clothes, your room. (Your mother would be pleased.)

Arch Rule 2. Time is of the essence. So, give yourself plenty of it. Getting the equipment will take time. Then making it work right will take more time. You’ll probably make your share of bubble cake, multi color mold, goop de jour, etc. Ask yourself: What did I learn? Keep a journal. Yep. Put in it what you did, exactly, what happened, and then think on paper about why it didn’t work. This is gold.

Do you know how much people are willing to pay for the journals of scientists, artists, and writers? Yours could be there. But you’ve got to train yourself to keep one. Besides, the science fair judge will want to see it.

Are we ready?

Now order some clean, yep, bacteria from an on-line store.