3 Easy DIY Biology Ornaments For The Whole Family!

‘Tis the season for cocoa, decorating, and festive music! But in the time of the pandemic, it also means, homeschooling and finding new ways to entertain ourselves and our family. What better way to combine these than with 3 super simple holiday decorations and biology ornaments you can make at home! These are great for a date night activity for the microbial obsessed or as a way to entertain and educate your kids on the unseen world.

In this post, we will lay out exactly how to create these 3 microbial holiday decorations including the ingredients, instructions, and teaching points. Supplying you with everything you need to become a microbial artist worthy of Instagram! Our holiday decorations include Petri dish string lights, 3-ingredient cinnamon microbe ornaments, and microbial garland.

1. Biology Ornament 1 : Petri Dish String Lights – by Jorji Siegmundt

Hi everyone! My name is Jorji and I am a graduate student in a master’s program, as well as a research associate in a biology lab. Oh yeah, and a wife and mom. I am working on a probiotics project at work, so I actually get to play with poop just about every day. And it. Is. Glorious! Questions about poop bacteria? I’m your gal.

Apparently one day after work, school, and child-wrangling, I had 2 minutes of free time in which I was able to scroll through Twitter. I came across a post about someone that had accidentally acquired 10mL beakers, instead of 100mL beakers. Of course, I had to read through the comments to see what other scientists had said.

Well, it turned out that he ended up making these adorable Christmas baubles using epoxy. Being the incredible nerd that I am, I thought that it was so cool and this adorable silly mistake became an instant holiday inspiration! So, I said to myself, “Self, I work in a biology lab. Where else could we take this?” My mind immediately went to Petri dishes.” Like I said, nerd. If you would like to make these mock microbiology trinkets for your lab (or home for that matter), here is what you will need:

Time to make: 2-3 hours

Drying time: 24 hours

Ingredients

• Protective gloves

• Mixing cups with measurements on the side, or small clear plastic cups

• Popsicle sticks

• Toothpicks

• Box of Epoxy Resin – I used Envirotex Lite®, found at my local craft store. It’s a 1:1 ratio, and very easy to use.

• Jewelry storage containers, or something to resemble Petri dishes

• Transparent resin dye

• Glitter glue or glitter paint

• Any decorations you might want to use. I used foil flakes and nail gems.

• String lights

• Hot glue gun

• Hot glue sticks

BEFORE YOU START, A Word Of Caution

There are a couple of precautions you need to take:

1. Please do this in a well-ventilated area. The fumes are strong and can give you a sore throat.

2. Use some kind of disposable gloves to protect your hands. Lab gloves will work just fine.

3. Make sure to follow all instructions on the package of whatever kind of epoxy resin you use.

4. Have something to protect the surface you are working on.

Directions

To prepare, first, protect your surface, layout your containers/dishes, epoxy resin, mixing cups, popsicle sticks, and put on your gloves.

Mix epoxy resin according to package instructions. Again, mine was a 1:1 ratio but yours may not be. You may need to warm it to room temperature, as well. The bottles I used both contained clear liquids, but they turned translucent with lots of bubbles when mixed together. Once epoxy resin is mixed, add the desired amount of coloring to your mix. For suggested microbiology accurate colors see our section on the microbial media teaching point.

For my first round of plates, I did lighter colors because that was the colors I had on-hand. For my second round, I used brighter/darker colors, just to add some vibrance and variety. Be creative! There is no right or wrong here! You can turn it into an educational point or just let your creativity flow, bonus points if you can do both!

Pour colored epoxy resin mixture into dishes. It will have a lot of bubbles. You can heat these briefly with a crafting hot torch if you like. I was afraid I’d melt the plastic, so I just left them alone and they turned out great. Anyway, this was just for fun. If I was going to sell them, I might have made a different choice.

You have about 25 minutes to actively work with the plates. If you choose to work with them after 25 minutes or you try to pop the bubbles after this time, you may leave marks on the top of the resin that you cannot get to smooth back out. If you try to add anything to the plates while they are not solid, such as beads or metal specks, be aware that gravity will eventually pull them to the bottom of the plate. I let my dishes sit undisturbed for about 24 hours, though I think you can probably decorate them sooner if you want.

Once the epoxy resin is dry, you can start to decorate! I wanted a variety of looks. Since I work with bacteria, I did a lot of plating, streaking, and quads, but I also chose to include some fungi-looking plates. If you're looking for inspiration, jump on the internet and Google quadrant streaking or your favorite culturable microbes.

Now for this part, I did not choose to use accurate bacteria coloring. I used what I thought would look good as a decoration and would stand out. You may want to do some gold on your red plates to represent hemolysis, yellow on your hot pink plates to represent the growth of S. aureus, green on red plates to resemble E. coli growth, or you could imitate Klebsiella pneumoniae growth on the blue plates using pink paint.

You can do fun stuff like streaking techniques with your paint. I use these techniques often in my lab when I am trying to isolate bacteria and obtain pure cultures. While the glitter glue or paint is still wet, you can add other decorations like the foil flakes or nail gems I used. Have fun with it!

Let your plates dry. Then, it’s time to hot glue! Once your hot glue gun is warmed up, you can add a little spot to your string lights and attach them to the plates. I chose to do it on the edge of the plates. Hang them up and enjoy!

Microbial Media Teaching Point!

Yellow – could resemble Phenylethyl alcohol agar (PEA) which is used to cultivate Gram-positive (have thick cell walls) organisms. Staphylococcus aureus, which can be found on your skin is a Gram-positive organism.

Red – could resemble a blood agar used to monitor hemolysis. Hemolysis is breaking down blood cells. When a microbe can do this the colony will have a clear halo around it. This is called beta hemolysis and it is something Staphylococcus aureus, a part of your skin microbiome, can often do.

Hot pink – could resemble MacConkey agar which is a medium used to distinguish between lactose fermenting and non-fermenting Gram-negative bacteria, or Mannitol Salt agar that selects for Staphylococcus.

Light pink – could resemble plates that use resazurin which is a chemical additive used to determine when oxygen is present in media.

Blue – which could represent Hektoen Enteric Agar used for Salmonella and Shigella, a common diarrheal disease.

2. 3-ingredient Cinnamon Microbe Ornaments - The Shapes Of Microbes

This super simple recipe for cinnamon ornaments is extremely versatile. It’s a fun project for adults and kids alike. It’s inexpensive and might even be free! This recipe uses ingredients you likely already have in your kitchen. The best part is it’ll make your home smell amazing all season long!

So grab your kids, your partner, or whoever else is in your household, and let’s make some microbe memories!

Basically, we will be creating a cinnamon dough that we can shape into cookies. This can be done in 1 of 2 ways, you can shape the cookies into microbial shapes or you can use a cookie cutter or mason jar cap to punch out the cookies. Then you can use a toothpick or other utensil to draw in some microbial friends. After a long bake on low heat, the dough will harden and you can stick these biology ornaments on a tree or around your house.

Ingredients

• ¾ cup applesauce

• ~ 1 cup of cinnamon

• 2 tbs of white glue

• Flour (optional if the dough is too runny)

• Toothpick

Optional ingredients

• Ribbon/twine

• Glitter glue, beads, other crafts supplies

Directions

1. Mix together the applesauce, cinnamon, and glue into a dough forms. If the dough is too runny add additional cinnamon or flour. If the dough is too thick add more applesauce. Depending on what applesauce you buy will depend on the consistency of the dough.

2. Knead dough until smooth and all ingredients are well incorporated

3. Roll out dough until it’s between ¼ and ½ inch thick. You can either do this with a well-floured rolling pin or stick the dough between some parchment paper. Alternatively, you can just flatten it out by hand.

4. Punch, or cut out the desired shapes. We used the top of a mason jar to punch out the larger cookies or the top of a spice jar for the smaller cookies.

5. Use a toothpick to create a small opening near the top of the cookie. This is where the string/ribbon will go in to hang it up so make so the hole goes all the way through the cookie and it’s big enough to stick your string/ribbon through (but don’t make it too big!).

6. Take your toothpick and draw...anything! You could go all the way through just make sure there is enough dough to hold the integrity of the cookie. If you just do surface drawings make sure you create a deep enough indention that you’ll still see it on the other side of baking it.

7. Place the ornaments on a parchment-lined baking sheet. Bake at 200F for 1 ½ to 2 hours. Alternatively, you can set the cookies out to air dry for 3-4 days.

Decorating Ideas: Types of Microbes

There is no limit to the ways you can decorate these cookies but of course, we did ours as microbes! There are two main shapes of microbes. We call the shape of microbes morphology. There are circular microbes we call cocci and rod-shaped microbes we call bacilli. Circles and rods are very simple to draw and by adding an eye and mouth you’ve now created a microbial friend to hang on your tree. Below are some of the ones we made.

3. Biology Ornament 3: Microbial Garland

This one is easy but does require some patience! Once you have your Petri dishes decorated, and your microbial friends etched into your cinnamon dough you can string them all together either on lights or strings. We added some silly face conical tubes wearing festive holiday hats, just for good measure. You can add whatever you want! Just string them all together and then hang them up on your mantel, your tree, or across your windowsill.

We’d love to see what you came up with! Try it out and tag us on Twitter (@microbigals) with your creation!

References:

Culture Media - Microbiology Resource Center. (n.d.). Truckee Meadows Community College. https://www.tmcc.edu/microbiology-resource-center/culture-media

Hektoen Enteric Agar. (n.d.). Welcome to Microbugz. https://www.austincc.edu/microbugz/hektoen_enteric_agar.php

Mannitol Salt Agar. (n.d.). Welcome to Microbugz. https://www.austincc.edu/microbugz/mannitol_salt_agar.php

About the author

Jorji is a graduate student in a master’s program for general biology at Point Loma Nazarene University in San Diego, CA. She also works at J. Craig Venter Institute, a nonprofit research lab, playing with anaerobic bacteria and studying microbiology.