Hi All! My name is Cass and I’m a new member of the SANDS Group here at ASU (pictured above explaining some cool science with my hands at the head of the table). I’m a PhD student in Biological Design, and will be helping out as a science advisor for some awesome new DIYbio projects at SANDS. Last week, we held our first bio workshop, doing a disc diffusion assay with some members of the community. This experiment allowed us to determine if different compounds have antibacterial properties, an important test when antibiotic resistance is on the rise.
To do the test, participants were each given a petri dish with agar media (bacteria food) and a tube of E. coli culture to spread on it. (*Fun fact! Almost all strains of E. coli, including the one we used, are harmless. In fact, there are millions of E. coli cells living happily in your gut right now). Once the bacteria were spread out, discs with antibiotics were placed on the plate along with materials participants were interested in testing. We used various soaps, a penny, and even garlic. These plates were then nestled cozily in the lab’s incubator, built previously at SANDS, so the bacteria could grow overnight.
After growing the bacteria, we can looked for zones of clearing in the lawn of bacteria around the disc/material placed on the plate. Are the bacteria growing right up to the disc? Then they’re resistant to whatever’s on it! Do you see a zone of clearing around the disc where the bacteria can’t grow? Then your compound has antibacterial properties! This test uses some basic microbiology to answer some important questions. It’s still used all the time in clinics to determine if a certain drug will work against a patient’s disease or not. We wanted to use this experiment for our first workshop to highlight the ability of any person to do such a powerful test, and bring attention to the important issue of antibiotic resistance. As our use of antibiotics increases, resistance to these drugs also increases. Searching for new antibiotics is an important area of research in which citizen scientists can participate. Just like bacteria are all around us, so are potential antibiotics.
We’re planning several more future bio workshops to involve the public in simple, empowering science, so keep an eye out!