My Experience at Greater Vancouver Regional Science Fair

My Experience at Greater Vancouver Regional Science Fair

If you told me last year that I’d be competing at a science fair, I would have probably laughed at you. I wasn’t even aware that science fairs were taking place in my area- sure, I’d heard of the Google Science Fair, but much of that seemed out of my reach. I had thought a lot about things I’d like to try and experiments I’d like to perform, but much of that was just imagination with no further action.  A year later and after a few months of interesting contaminations, a lot of pipetting, helpful mentors to guide us, and many sky train rides to Science World, on April 10-12, I had the opportunity to attend my first science fair. My partner, Jessica of Marie Curious, and I had spent months carefully preparing for this moment; our poster: flawless. Our graphs: perfect. Our presentation? Poised, fluid, and engaging. When I say this, I mean we may or may not have finished gluing our poster together at the fair itself, and that I was “pretty sure” I could make it through presenting our project to a judge without dropping my petri dish of gelatin, flour, and beef bouillon- a convincing model of Kirby Bauer Antibiotic Testing.

Me, feigning calmness and confidence before the fair.

Me, feigning calmness and confidence before the fair and not yet dropping our gelatin models.

Our project was titled Essential Oils: Natural Prevention to Dental Caries? and was the product of research conducted at Science World since January. The aim of our project was to compare the effects of various essential oils (clove, tea tree, peppermint, and oregano) to that of fluoride at inhibiting the biofilm formation and growth of cariogenic bacteria. Was that last part confusing? Essentially, a biofilm is a colony of bacteria protected by a sticky matrix that makes it much more resistant to antibiotics. These biofilms adhere to the surface of teeth and are the cause of plaque buildup and cavities (also known as caries). We wanted to compare the abilities of fluoride, a common additive to dental products which some papers identify as having antibacterial effects, to several essential oils at keeping a biofilm from forming/growing, as well as inducing cell death of the evil, cavity causing bacteria.

After identifying Streptococcus Mutans as the primary causative agent in the formation of dental biofilms, we selected a structurally similar, non-pathogenic bacteria that we could work with in the lab space at Science World: Lactococcus Lactis, a common bacteria present in milk products and the Wisconsin State Microbe. Using the l. lactis, we performed a biofilm assay and a disc diffusion (Kirby Bauer) assay to investigate two independent mechanisms; whether the oil inhibited the growth of a biofilm, and whether the oil could kill the bacteria.

Jessica working at Science World

Jessica working at Science World

The biofilm assay involved placing our four experimental oils (clove, peppermint, oregano, tea tree) with fluoride, our positive antibiotic control Tetracycline, and our negative control which was nothing added in a 24 well plate along with our bacteria and media. After incubating for four days, we washed and stained each well with safranin, a colourful pink stain which I was able to replicate remarkably well with food colouring in our gelatin model. The resulting stained biofilms were assessed using a colorimeter, which simply shone light through our samples and measured the percent transmission of light. A thick biofilm would result in greater absorbance of the light and lower transmission, and little to no biofilm would result in a high percentage of light transmission and thus lower absorbance of light. This data gave an indication of the density of the biofilm.

Second, we combined l. lactis cells with sterile water, which we spread over plates containing agar. One of our experimental variables (oils or fluoride), as well as our controls (tetracycline and nothing added) were pipetted onto sterile filter paper discs and placed on the plates. After a 48 hour incubation period, a “zone of inhibition” or “halo” of cell death could be observed on controls and variables that killed the lactococcus lactis. The zones of inhibition were measured with rulers (carefully and in replicate!) and recorded.

After a crash course in Microsoft Excel and a lot of late night writing, we had created a representation of our results. Our conclusion: in both tests, tea tree and peppermint oil displayed the greatest efficacy at inhibiting the biofilm and killing the l. lactis bacteria. Surprisingly, fluoride had almost no effect on the bacteria, suggesting the debate that the concentration of fluoride in toothpaste is antibacterial is false. Another interesting result was that oregano oil inhibited the formation of the biofilm effectively, yet did not kill the bacteria directly. Perhaps, it affected the biofilm’s matrix, or adherence to the well. Our results posed opportunities for future research which we’d like to look at in the future, such as working with Strep. Mutans or identifying the active agents in essential oils that are antibacterial.

Our months of work at Science World had finally materialized into a posterboard adorned with colour coded graphs, stock images of essential oils, and diagrams composed exclusively by the “shapes” tool on Photoshop. As I drove out to the University of British Columbia (UBC) the first day, I was a blend of excitement and nerves. Thoughts of a PhD educated expert on oral microbes asking questions better suited to a graduate student about our project turned my stomach as I thought about the two three hour judging rounds that were to take place that evening.Walking into the hall that housed the intermediate and senior projects, I felt intimidated by the creativity and detail of others’ projects- all I wanted to do was walk around and marvel at what other people had thought of, not prepare for the first round of judging!

Our board, finally completed!

Our board, finally completed!

As judging commenced, I found many of my nerves fading away. When I practiced in my room the night before, I found my mind searching for basic words and hands shaking at the thought of presenting our work. However, once the first judge asked Jessica and I about our project, I was able to explain our research without nervousness-  we knew our experiment better than anyone else, and I was eager to share what our results had been. What so many people had told me had turned out to be true; sharing my work with other people was something I enjoyed doing.

The first day of the fair was largely for judging- however, the following two days were more fun than competitive. We went on tours of labs at UBC, saw a magic show, and could compete against other students in trivia games. I went on the tour of Boreal Genomics, a company who has developed technology that is able to extract and isolate DNA from challenging samples, such as petroleum, as well as a device can detect mutated DNA from blood samples- essentially, a type of blood test for cancer. Touring the lab gave us students the opportunity to see the amazing work that’s taking place at UBC behind the closed doors of laboratories. Out of all these activities, my  favourite part of the fair was spending time with my friends from Future Science Leaders- although there was no one from my school there, there was always a group ready to eat fries in the basement of the Student Union Building or share our nervousness in how judging had gone. Having a group of people I knew with me at the fair made my experience that much more positive.

After nearly three days of explaining, presenting, and fun, the pinnacle of the fair arrived- the awards ceremony. As hundreds of fidgety students and their parents filed into the Norm Theatre, I had mostly accepted there was a good chance we were not going to win something from the fair- it was my first time, and so many of these projects were amazing! (I think I have a serious case of “Imposter Syndrome” because at most events and opportunities I receive I find myself asking “how did I manage to get here?” but that’s beside the point). As the names for awards were called, my partner and I were called twice- we won a bronze medal, and were nominated for a BC Hydro Scholarship. After a lot of long hours and hard work, receiving an award was surprising but amazing! As exciting as receiving awards ourselves was the success of my fellow Future Science Leaders- continually the names of friends were called onto the stage to receive medals, scholarships, money, and even a trip to the Canada Wide Science Fair.

The Senior Awards Ceremony Stage

The Senior Awards Ceremony Stage

Attending the GVRSF was rewarding, exciting, and taught me a lot about how science fairs work. Most prominently, it motivated me to strive for greater success in the future and I’m already thinking about what I’d like to do next year as a project! I want any students reading this to know that even if they’ve never worked in a lab before, or their teachers don’t know science fairs exist, that yes, you can do a science fair! No one from my school (dare I say entire town?) had ever entered a science fair, and it was an entirely new experience for me which I’m so thankful to have been a part of.

Now that the fair is over, I feel bored; what used to occupy much of my spare time is finished, and I feel both relieved and sad. Now that I think about it, I think I have an idea for next year… I guess it’s time to start researching again!

As a parting note, congratulations to everyone at the fair! Also: to those who are seasoned veterans and those who have just realized that science fairs exist, I hope to see you next year!


For more information on the fair, visit the GVRSF site.

Role of S. Mutans in biofilm formation here.

Biofilm assay procedure used here.


  1. Christina Cheung says:

    Congratulations on your success at the science fair! Are you going to narrow down your project this year in preparation for next fair?

  2. Lauren Dobischok says:

    Thanks Christina! 🙂 I’m not sure if I’m starting a new project with a different focus for next year, or doing a continuation. I’m already beginning to think of what to do for next year’s fair so I’m prepared to submit my abstract to fairs with early application dates. Congratulations on your work at the fair as well!

    • Jessica Li says:

      Yeah that’s a good idea! Since we changed our topic halfway (after the curcumin wouldn’t dissolve and also wasn’t sterile) we had to rush our abstract.

      If we did choose to do a continuation, there would actually be so many things we could! E.g. repeating the experiment with tricolsan and s. mutans, or focussing specifically on the carvacrol and thymol found in oregano oil.