In 2025, I began my doctoral research in translational cancer genomics at Charles University in Kari Hemminki’s group. My project aims to uncover genomic biomarkers that predict or explain non-metastatic to metastatic transition in colorectal cancer (CRC).
To do so, the project is broken up into two arms: immunohistochemistry and genomics. Last fall, I worked alongside my colleague, a postdoctoral researcher, to process 44 formalin-fixed, paraffin-embedded tissue samples from CRC patients for DNA isolation and subsequent sequencing.
During the experiment, I realized that 10 of my 30 samples did not look as expected. When I checked my reagents, my stomach dropped. I had mistakenly added absolute ethanol to my samples instead of the isolation mixture, which was in the tube next to the ethanol.
It felt like a nightmare. All I could think about was that I had wasted 10 precious human samples, but my colleague stepped in and said, “Okay, let’s hold on.”
At this point, I did not know it was possible to request backup samples, but she spoke to the histopathology department, and they needed a week to check. In the meantime, we tried to troubleshoot if there was any way to salvage our samples, but to no avail. So, we completed the remaining samples and began planning our next steps.
We decided to wait for news about the backup samples—and hopefully process them—before reporting the incident to my supervisor. It was anguish, because I kept replaying the experience in my mind. Mistakes happen, and this one was rather costly, but it especially felt like the stakes were higher than ever. I had only recently joined the group and felt that I had to prove myself in this new environment.
My supervisor must have sensed something was wrong, because a few days after the incident he asked if everything was okay. I froze. Then I admitted it wasn’t, and I explained the accident and the plan I had put in place to fix the mistake.
In response, his words and approach were incredibly warm. He emphasized how serious it is to lose human samples, and I took full responsibility. Since that conversation, I honestly feel the experience brought us closer.
In the end, thankfully we got nine out of 10 backup samples, which brought our sample number to a cool 100. Then, I prepared and sequenced DNA libraries for these stage II colorectal cancer samples.
Afterward, I commiserated with my lab colleagues, and we swapped horror stories. When I told them it was 10 samples, they said, “Only 10?” That perspective helped.
Later, when a new team member joined the lab to focus on wet lab work, I told them that at some point during their PhD, they will inevitably make mistakes, and that’s okay.
Looking back, the day felt catastrophic, but it gave me a different perspective. It’s only natural to not always operate at 100 percent, but it’s rarely the end of the world. I can even laugh about it now. Thankfully, it all worked out in the end.
This interview has been edited for length and clarity.
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