By Michael Shang
It’s been an eventful month and a half. When we last left off, a new morphology had cropped up in my MTL dilutions (despite the previous step having a seemingly pure population and after it had already been subjected to around 8-ish streakings), and I was determined to find out what caused it. Weeks later, much information has been gleaned . . . but none has helped me move forward. Alas, after a semester of lab, and after coming in every day, Monday through Thursday, to squint at my plates and curse the Phage Gods once again, little progress has been made.
And yet, the information I’ve found is invaluable — the phages that make the new big plaques take two days to incubate, as I found out from coming in every day (e.g., I would plate the big ones on Monday, come in on Tuesday and notice that they made tiny pinpricks on the plate, and then come in on Wednesday and see their size explode to the usual “big” size). And, perhaps most important, I’ve found that yes, the two different morphologies are indicative of two different phages, rather than one phage behaving differently.
That information came, funnily enough, from EM–electron microscopy–which is supposed to be one of the last steps we take in the process of phage hunting. Instead of doing EM on an HTL, I ended up doing it on my MTL. And the results are simultaneously encouraging and discouraging. Because the tails are 20 nm apart in length (190 nm vs 210 nm), the two plaques are definitely indicative of two different phages. The good news is that it confirms my suspicions; the bad news is that it means I have two phages. Another interesting thing: even though there seems to be so much more of the “small” phage, when I went to do EM, the big one was easily visible on the screen; finding “smalls” was actually quite hard to do (it didn’t seem like there were many of them).
Alas, after sticking with my small inverted-bullseye-morphology-phages for an entire semester, I’m forced to conclude that I must switch to the big ones. The decision was not an easy one, and I almost shed a tear — kidding, kidding (I exhausted my reserve of those a long time ago).
Even if I don’t get graded for it, though, I still want to figure out what’s going on. Even though I’ve had a myriad of woes, I think this is the coolest thing about science: when stuff doesn’t go your way and weird stuff pops up, you could be on the brink of discovering something. Anyway, let’s hope that, next semester, I’ll have more luck.