Yogurt as Biotechnology

For our very first course we will put microbes to work making yogurt. The process of yogurt making itself is super simple, and takes only one lesson to cover completely. In the rest of the course, we use the yogurt as a jumping-off point to introduce basic synbio tools and concepts.

We jump immediately into the laboratory and start following simple protocols. We will return to the laboratory many times, and eventually our goal is to be fully immersed in synbio lab life. However, at this early stage it is not important to know how everything works. Sometimes, you may be able to guess from the context, or figure out what is happening by doing your own research online. Other things will become clear in future experimental videos. For the first course just sit back, relax, and get a feel for things.

What the heck is this thing?

Unit 1: Fun with Fermentation

In Unit 1 we make yogurt in the lab and we discuss the chemical changes that happen to milk as it is transformed by growing bacteria. We’re going to take something that you’ve seen before in the kitchen and use it to introduce lab equipment that may be new to you. In the same way, we want to transition from familiar language to a more specialized scientific vocabulary. Anyone who has tasted yogurt can recognize that it is sour. As scientists, we talk about sourness using precise chemical terms like “pH.” By talking like chemists we start to think like chemists, unlocking powerful conceptual tools for understanding yogurt or any other biotechnology.

Yum yum yogurt

Unit 2: The Care and Feeding of Microbes

In Unit 2 we talk about what it takes to grow microbes. It turns out that this is pretty easy to do. Microbes love to grow and they can do it even under difficult conditions. We need to get good at growing microbes because it is something that almost every synthetic biology lab does almost every day. Often, this is because want to genetically manipulate the microbes themselves. Synthetic biologists love microbes for several reasons.

  1. They are easy and cheap to grow.
  2. They grow quickly, allowing you to see the results of your work right away.
  3. They are well understood, thanks to generations of research motivated by #1 and #2.
  4. They are powerful, with metabolic and genetic capabilities not found in other organisms.


Biologists love microbes so much, they all buy microbe plushies and kiss them every day.

Even if your goal is not to manipulate microbes directly, you are likely to encounter them in any synthetic biology research project. Because even when microbes aren’t the focus of our work, we still use them as a tool. Microbes are like little DNA factories. In evolutionary terms, that is basically their only job. Every time a cell grows and divides, the DNA inside also has to replicate. That includes any synthetic DNA that we have put inside. So you can transform a single microbe with a single piece of DNA, come back the next day and find millions of microbes with millions of pieces of DNA.

Unit 3: Let’s Get Quantitative

In Unit 3, we start to introduce simple measurements and math. At the most basic level, this is just part of life in the lab. As scientists, almost everything we make and do is precisely weighed and measured. It is just a question of getting used to the common ways that we weigh and measure things and the routine calculations that we do, for example to prepare a solution at a specific concentration. If you are new at math, these calculations are a good way to flex your brain muscles. If you are a math expert, you’ll still want to practice these a few times to avoid careless mistakes in the lab.

Math is a tool in synthetic biology, but it is also a way of life. We are an engineering discipline, which means we try to ask quantitative questions and think mathematically whenever possible. If we know that yogurt contains bacteria, we naturally ask: How many? So in this section we also look at a method for counting the many millions of bacteria in a sample of yogurt.

This cat is a synthetic biologist.

Unit 4: Stay Safe Out There

I admit it: it is weird to have yogurt in the lab. The lab is a place of latex gloves, weird-smelling chemicals and unexplained mysteries. It is not the kind of place where I want to see anything that looks like food. But there are plenty of genetically modified foods on the market today that did come from a lab, at least at their origin. Of course, they didn’t come directly from the lab to your plate. They went to a farm first, just like normal food. But you know what I mean. It make s people uncomfortable.

The creation of GMOs, especially for food, has provoked skepticism and protest from many groups around the world. In these courses, we won’t try to decide who is right or wrong. But we will take the time to consider different opinions and think about how they interact in a global conversation about GMO ethics. It is our job as scientists to watch out for our colleagues, and ourselves, to make sure that what we are doing is safe and not evil. This means staying informed about the human impact of our work.


Never question the poster.

Moving On

By the end of the first course, we will have touched on all the different disciplines that are part of the study of synthetic biology: Biology, math and human practices. If you felt comfortable following the videos, you are ready to move on to Course 2: Your First GMO. If you felt totally lost in any of the subjects, don’t give up! Now is a good time to fill in any gaps in your background with the online resources below. Or, your could post a question in our forum. It isn’t easy mastering multiple major scientific domains simultaneously, but it is so so worth it.
Outside Resources