“Possibly the Most Critical Day”

I woke up early this morning to go on a jog. I’m not normally much of a runner, but I’ve enjoyed exploring the campus and exercising some the past few mornings. After getting ready for the day, I headed over to the dining hall for a quick breakfast paired with some chai tea I bought at Target this weekend. From there, we headed over to the lab.

It was protein purification day. As today’s lab instructions read, “This is possibly the most critical day of the whole project.” We were warned not to spill our protein – an entire week’s worth of work that we would need for the rest of the program. No pressure.

Walking over to the lab
Dr. Hall explaining the chromatography system

After Dr. Hall explained the lab, we split into our groups to begin. As we all learned, a rubber policeman is not an elastic-like cop. It’s just an intriguing name for a rod used for mixing samples.

In the middle of the lab, one of our TAs, Colin, came over and informed me that I had won last week’s Question of the Day competition. We have a riddle or challenge each day, and the winner each week receives a prize, with a grand prize at the end.

Eric mixing our sample with a rubber policeman
My group mates, Brian and Eric, making shadow puppets on the projector as we wait for our cells to lyse

Once our cells had lysed, we put our samples in the centrifuge to separate the protein.

Dr. Das explains the importance of balancing the centrifuge…if it isn’t properly balanced, explosion may ensue

The cells were done spinning in the centrifuge when we learned that the sample was not as amber-colored as expected, meaning there may not have been enough protein. We feared the worst, but after running a test known as a Bradford assay, we found that we had enough protein to continue with chromatography. The Bradford dye by itself was gray-ish, but when we added some of our centrifuged sample, the dye turned blue due to the presence of protein.

A comparison of the control (left) and experimental (right) samples from the Bradford assay, featuring Brian
The Akta Start chromatography system

After about 90 minutes, the chromatography ended. But to our disappointment, our target protein was not shown in the absorbance graph. Our protein was likely insoluble, so it was not found in the mixture we used in chromatography. The other group analyzing the same protein as mine found the same results. In other words, our protein purification failed. But at least we learned that our original protein is insoluble under the conditions we used.

Our chromatography absorbance graph…our target protein wasn’t there

Dr. Hall spoke with my group and the other group working with the same protein. We decided to repeat our labs using a cell culture from a previous year of SSP. We can continue with that protein for the remainder of the program. It was certainly a set-back, but we all felt determined to try again. And as Eric said, “We’re going to be better at purification than any other group”. We’ll simply get double the experience.

We restarted by making some more media where our cells would grow. And we even got a behind-the-scenes trip to the autoclave in the basement.

Dr. Das showing us the autoclave machine

After dinner, where I received a Purdue mug as my prize for winning the Question of the Day challenge, my group went over to Dr. Hall’s lab to get some new protein. But we were met with a surprise. The floors there just so happened to be being waxed, so Dr. Hall’s lab was blocked off, and we couldn’t access the proteins in his room. Luckily, Dr. Hall had some protein in one of the teaching classrooms downstairs. We are now working with protein from another species. Hopefully this one will work better.

Despite such obstacles, we made it back to the lab building we are normally in. We successfully finished the lab work for tonight, and we’ll continue tomorrow. We should be able to catch back up within a few days.

Groups 11 and 12 preparing to walk to Dr. Hall’s (newly waxed) lab
Finishing our lab work for tonight

This was certainly an eventful day. Perhaps the most critical lab day didn’t go fully as planned, but such is science. I’m so glad to be with wonderful group mates as we continue our learning process, and everyone else’s determination makes SSP inspiring and supportive.

Hi! I’m Payton, and I’m from Washington state. In addition to science, I love competing in speech and debate and math competitions, doing ballet, and spending time with my friends and family.