Despite our best intentions, all of our planning and foresight, science has its own idea of what is going on and what will happen. Instead of hearing “Eureka!”, science takes the Calvin and Hobbes approach and goes “boink.” This is pretty much the summary of my last laboratory exercise with my students for this semester… Lab #9.
I wanted to have a pretty cool experiment for the last Micro lab, and I had been saving one in particular to use as the “grand finale.” As I have experience with bacteriophages from my undergraduate research days, I was going to have my class isolate phage from local water samples, and visualize them on lawns of bacteria using a technique called top agar overlay. In the end, they would have plates that look like this:
Essentially, the clear spots (or holes) on the plate are where the bacteria were lysed by bacteriophage, viruses that infected and killed the bacteria. I think its cool, its not too difficult to do, and the results would be variable. In other words, this was not a “cookbook” experiment where I would know what results the students would get. The plaques could be clear or turbid, big or little, few or many… in the end, we should see a variety of results. This would more closely resemble the real scientific process and the “unknown”, and I wanted the students to experience that.
So! I was ready to launch this experiment! I had the materials prepared, and I even went out to several local water sources (ponds, lakes, streams) and collected fresh water samples. Two other individuals brought in water samples for me, so I had enough samples for each pair of students to have a unique source to test. I had a YouTube video for them to view before class that demonstrated proper use of a piece of laboratory equipment, and I had prepared everything that we needed in advance, so when the lab day arrive, I just walked in and got started. Or so I thought.
My first indicator that things might not go well was when I poured a sample top agar overlay plate. The idea is that we mix viruses and bacteria together, add it to a tube of warm molten agar, and pour that mix on top of a nutrient agar plate (top agar overlay). This method allows for visualization of the plaques, indicating the presence of phage. As phage are the most abundant biological entity on the earth, I had no doubt that we would see at least a few plaques within the entire class. However, I did not expect what happened next… the molten top agar did not solidify. It cooled into a gooey gel-like soup that slid off the plate as soon as you tilted it to the side. Not good. But at that point, it was too late for me to make up a whole new batch for the class. I decided that we would procede as planned, but would pour the top agar and not move the plates, so that the agar would not have a chance to slide off. With a few last minute alterations to the procedure that I announced to the class, I managed to get the students through the first session. Now I just prayed that the bacteria grew overnight and some would be killed by phage, so that we could see plaques the next day.
Twenty-four hours later, I stopped in the lab before class to get a sneak peak of our results. After looking at nearly 40 plates, I found only one with plaques on it. And they didn’t even look all that great on that one plate. My heart sank into my stomach… my lab was a huge flop. I was disappointed that we did not have gorgeous plaques, and that some of our plates looked more like ugly wrinkled jello that smelled horrific. All of my other labs went off without a hitch- why did the last one have to go down in flames? Class was to be an hour today, but it would take them all of 30 seconds to see that their plates were crap. How would I deal with this???
Fortunately, I am a Girl Scout. And paranoid. Last night, my paranoid self decided to put together a lecture presentation to fill the class time, in the event that science went “boink”. So I was prepared to shuffle the students from the lab to the classroom for some post-lab discussion. The negative data became a teaching point and a launching board for problem-shooting: what may have gone wrong? Why didn’t we see more plaques? What happened to the top agar? (the answer to the last one- the agar is older than I am… looks like we need to order a new bottle!) Most importantly, though, the students understood that you do not always get good usable data from science experiments; sometimes things happen differently than we expect and we have to figure out what went wrong. That’s science. That is why it is called “research” and not just “search”… because you often end up doing it over, and over, and over again. Were the students phased by the lack of results? No. We talked about the lab, and moved on to spend some much-needed extra time covering lecture material. So in the end, it worked out and a lesson was learned: the students learned that science is not always perfect, and I learned that adaptability and preparation is key for making things work in this profession.
Evolution of Academia 