Team:MIT/Results
Biofilm Assays
In order to quantitatively measure the effect both of our system and selected output protein on the S. mutans biofilm, we had to first characterize biofilm accumulation without any added deterrents or inhibitors. By characterizing biofilm growth under our lab’s conditions and the resources available to us, we could better understand the effect of our synthetic system.
To actually get our hands on the bacteria S. mutans, as well as protocols and tips on how to best observe and treat the species, we met with Dr. Caroline Ribbeck from the MIT Ribbeck lab, which studies the mucus barrier and how it selectively allows and blocks different molecules and pathogens from passing through it.
Dr. Ribbeck gave us our S. mutans strain (UA159) and our protocol for tracking CFU (colony forming units) growth.
Initially, we wanted to optimize growing conditions to maximize the amount of biofilm formed. We learned from existing literature and Dr. Ribbeck that the way in which S. mutans grows on polystyrene (the material of our 96 well plates) is similar to the way they would grow on human teeth. While the shape and placement of S. mutans in our experiments were not exactly like that of the human mouth, we assumed our setup was a good model of the environment our bacteria naturally exist in.
For our experiments we varied sucrose concentration, growth media concentration, S. mutans volume, and incubation times.
In our lab we consistently used proper PPE depending on what materials we were working with. Every team member was also required to go through lab specific trainings to be allowed to work with anything in the lab, and some of the team members were trained separately to deal with the s.mutans in the lab. While using the S.mutans we had a different set of procedures due to the bacteria’s vulnerability to contamination. This made it so that we used multiple sets of gloves during our experiments and also used a bunsen burner to decrease the likelihood of contamination.
Safe Lab Work