Raising the Minimum Phage

By Michael Shang

Ah, Phage Hunting. That two and a half hour class/lab, filled with CiDecon art, rushing to snag Top Agar before it runs out, flagging down Dr. Schildbach and the TAs before someone else gets to them, and gathering as many plates, pipette tips, and M. smegmatis tubes as possible before having to turn on that infernally hot Bunsen burner.

It’s been an interesting year so far, to say the least.

From the first day of class, frantically gathering soil from the ground in front of FFC, five minutes before class (and breaking my spoon in the process), to the fabulous 5-cent disposable glass pipette tips (I was equally astounded by their inexpensiveness…and felt way less guilty for going through so many of them), phage hunting has far exceeded my expectations.

“Oh, that looks cool!”


(A typical lab conversation)

We started with direct plating (lol, did anybody’s work?) and making our enrichment culture. After filtering and performing serial dilutions, the entire class listened as Dr. Schildbach told us what we should notice — obviously, the plaques should decrease in number as the dilution becomes more pronounced.

And obviously, I should totally panic when my plates showed the exact opposite trend.

Fortunately, cooler heads prevailed, and I found that the reason for the weirdness was just the sheer amount of phage in my sample-that same sample found in the hard, dry dirt behind concrete near FFC. Go figure. So anyway, I just diluted further and everything was right as rain.

Yet for all the merriment and all the amusement, tragedy has also struck my phage hunting. After six — SIX — streaks, I proceeded to attempt to make my MTL. But lo and behold, new morphologies cropped up! In addition to the standard inverted bullseye morphology, there were new dots, about ten time the size of the tiny bullseyes that cropped up. At first, I asked myself,

Then I realized that I had nothing to worry about- after all, the big dots were quite possibly just the appearance given by a bunch of phage concentrated in one location. To assuage my fears, I both continued in my MTL journey as if nothing was wrong and streaked the big dots, to see what would crop up.

And then, the next class, I saw that they were TOTALLY DIFFERENT.

That means that there are at least two different phages with which I’m working right now! So as of now, I’m still trying to isolate the phage with the inverted bullseye morphologies-unlike most things, having the smallest amount of phage (that is to say, just one morphology) is ideal. Once I do that,  I can finally make that MTL, make an HTL, and eventually even image it!

Well, that’s all I have for now. Stay tuned for updates on raising the minimum phage!

This entry was posted in From the Phage Hunters. Bookmark the permalink.