Gnomo Habilis: Completed DIY Projects (Temporary): Petri Dish Science and Art Craft: Original Lesson Plan

Petri Dish Science and Art Craft

Original lesson for informal educational environments by Rachel P. Riendeau

First used at Knight Memorial Library's Science Craft Mania, July 21, 2014

Providence, RI

25 minute sessions

GATHER: Supplies for each student.

1/2 plastic Petri dish (via online suppliers) OR bottom of clear round plastic bottle/lid

1 circle, traced in petri dish, of 2-4mm thick craft foam sheet

1-3 toothpicks

1 washable cup

1 permanent marker

washable markers

PVA (Elmer's) glue

glitter OR glitter glue

color print outs of interesting bacterial growths on Petri dishes

sample of finished craft

optional: small items (flat back rhinestones, shapes punched from leftover foam, etc.), scissors (older students), long Q-tip/cotton swab (for demonstration)

SHARE: Briefly present to your students (about 5 minutes).

Can you see all the germs on my arm?

Neither can I. There's lots of good and bad germs on our skin, in our bodies, and in the world but they're too small to see with your eyes. You need a microscope,. or you can see them when there are hundreds and hundreds living together in groups called COLONIES.

Have you ever been to the doctors when your throat hurts and they take a long Q-tip like this (demonstrate) and swab the back of your throat? That's because they're taking some germs from your throat to see if any are STREP (Streptococcus pyogenes) germs.

Scientists feed the germs, pouring different types of food, called AGAR or GROWTH MEDIA, into small clear plates called PETRI DISHES. Then they transfer the germs from the Q-tip to the food on the plate by STREAKING THE PLATE, like this. If the germs like to eat that kind of food in the Petri dish, they will grow into COLONIES, which look like dots, all colors and sizes.

Today we're going to imagine what COLONIES of different germs look like. First put the AGAR, here, into the PETRI DISH. Then use your imagination and markers to draw colonies on the AGAR. Often, more than one kind of germ grows on a Petri dish by accident. This is called CONTAMINATION. To make your Petri dish more interesting, contaminate it: make more than one kind of pattern. Finally, put glue and glitter on the toothpick to STREAK THE PLATE. You can also make glue dots or glue on different things like dots and gems to make more COLONIES.

Be careful to only use a little glue when you streak the plate so it will dry. I will come around to label your Petri dish with your name and the name of your germ--remember STREP, for example-- when you're finished, so start thinking of a good name. Any questions? Okay, ready to grow some beautiful germs?

LEARN: Vocabulary list for fun, for the board or a hand-out.

microbe bacteria Strep microscope colony Petri dish

agar growth media streak the plate contamination culture

microbiology

REPEAT: Guide with structured directions as needed (15-20 minutes).

1. Put your circle of agar, the foam, into your Petri dish. Glue it down if it isn't snug.

2. Draw patterns of dots, lines, squiggles, and other shapes with the markers on your agar.

Remember, you can have more than one kind of bacteria on a contaminated plate, so be creative.

3. Squeeze some glitter glue into the washable cup. Take a toothpick, dip it in the glue, and carefully dot or drag it across your Petri dish to streak the plate. Make more patterns.

4. You can also use the toothpick to dab dots on glue on small, flat backed items to stick bigger colonies onto your Petri dish.

5. Let me know when you are done. I'll write the name of your germ(s) on the back of your Petri dish, as well as your initials and the date, with the permanent marker. This label reminds you what and when the germs "grew," an important detail for real scientists.

6. Clean up.

SHOW: Real life examples. Google Images has great ones, or send me a message for those I've found.