Course 1: Making Yogurt the Scientific Way

Goals for this Course

  • To demonstrate basic bacterial culture techniques.
  • To introduce math as a tool for biology.
  • To consider the safety, ethics and human impact of synthetic biology.


Key Terms Covered

  • Fermentation
  • Glycolysis
  • Denature
  • Growth Factors
  • Luria-Bretani Medium
  • Agar
  • Autoclave
  • Centrifuge
  • Pasteur Pipette
  • 50 mL Falcon tubes
  • Kim Wipes
  • Petri Dishes
  • Tryptone
  • Yeast Extract
  • Molarity
  • Moles
  • Copy Number
  • Milli- (m)
  • Micro- (μ)
  • Nano- (n)
  • Electronic Pipettor
  • Pasteur Pipette
  • Vortex Mixer
  • Parafilm
  • 1.5 mL Eppendorf Tubes
  • Pipetman
  • Disposable Tips
  • Electronic Balance
  • 50 mL Falcon Tubes
  • Kim Wipes
  • CFU
  • Petri Dish
  • Taboo
  • Hippies
  • Neckbeards



Hi everybody! Welcome to Synthetic Biology One. In this project we are making yogurt. This is something you can do at home, in your kitchen, with no prior training in biology. Many of you have even done it before. Or maybe you had a weird aunt who liked to make their own yogurt. I know I did. And why not? Yogurt is delicious, good for you, and popular all over the world.

Now some of you are thinking: What makes yogurt a part of synthetic biology? When do we start making GMOs? Well just calm down hot shot. We’ll get there. But you’ve got to walk before you can run, and yogurt is a great place to start playing with biology.

This project, we’ll learn the basic theory and techniques of microbial culture. In synthetic biology, microbes are our tool. And like any tool, we need to take good care of them and respect their limitations. What do we feed bacteria? How do we grow them?

We’ll also get in the habit of thinking about our work quantitatively, the way that engineers do. How many bacteria are in my yogurt? How many should there be? How long do the bacteria take to grow and how does the population change over time. The answers to these questions require math. We use math everywhere in this field, so we might as well introduce it here.

Last but not least: we chose to introduce synthetic biology through yogurt because it is provocative. Yogurt is something that we eat, something that most people see as wholesome, natural and safe. But those words are not always used to describe genetically modified organisms, or GMOs.

But GMOs are coming to the kitchen. They are already a part of how we eat. The work we do as scientists will affect human lives and human health. In this course, we won’t ignore that fact. So we chose a food product for our first project to remind us that bacteria are all around us every day and even inside of our bodies. When we make a change to bacteria, it matters.

Can you make and eat genetically modified yogurt? The short answer is no. In fact, you should never eat anything that comes from a lab. We certainly won’t be eating anything that we make in our lab. Our lab is not food grade and is full of dangerous stuff.

But if you’re following this course at home, you absolutely can make and eat yogurt in your kitchen. When you’ve completed this project, you’ll know exactly what to do. Any along the way, we’ll develop a deeper appreciation for the mathematics and biology of bacterial growth.

So until next time – stay fresh!


Course Curriculum