"Negative" Result as Significant Result


In my past lab experiences, I frequently obtained insignificant results or results that opposed my original hypothesis. When this happened, I would look through my lab notebook, trying to find any small mistakes that would suggest a potential experimental error. On the other hand, when results came out to be significant, I would just happily accept it. For the first time, I was hesitant to call a result significant. When I looked at the specific activity of our target protein, FKBP12, I was really confused on how there could be negative activity in several of the conditions we tested. When we ran a t-test between the control (FKBP12 only condition) and the condition with FKBP12 and ligand 13, we got a p-value less than 0.05. But, the condition with ligand 13 had the most negative specific activity. How can we call a result significant when it doesn’t make sense at all? Being a stubborn person who would not accept anything that does not make sense to me, I embarked on a journey to refute this significant, “negative” result. 

I quickly cleared my desk, leaving only a pencil, a calculator, and a stack of scrap paper. With these, I recalculated the specific activity of all conditions by hand, thinking that Excel have made a mistake in the order of performing the mathematical operations. When the number turned out to be the same as the ones generated by Excel, I then went through all the PPIase data files from the other teams, trying to see if there was an error in their calculation (since the specific activity was calculated from pooled data). After a few hours of searching through the files and finding no error, I emailed Noreen, asking if I should just take all the negative activities to be zero activity, which would then make all results insignificant. After receiving the response that I should report the actual data as they are, I started to believe that our result may have some significance.

When I finally started to accept and feel excited about this significant “negative” result, all my excitement was suddenly extinguished by the Kd value of rapamycin-FKBP12 binding. We found that our Kd value was significantly different from the actual Kd. This meant that there was a huge error in our experiment, and everything that was concluded from our results cannot be concluded. I spent so much time convincing myself that my “negative” results may actually be significant, only to find out at the end that my findings are completely invalid. 

Nevertheless, I learned from this experience that I should generate and analyze all my data before I start interpreting what they mean. In addition, I should look over all results, even ones that are significant and supportive of my hypothesis, to make sure that they are valid and because I learn the most in the process of going through all the procedures and trying to find potential errors in them.

Comments

Post a Comment

Popular posts from this blog

Don’t judge a module by first sight!

Different from Module 1 and Module 2, Module 3 is less molecular biology focused and not directly related to medicine. At the beginning of Module 3, I thought that I would enjoy this module less as it seemed less relevant to my primary interest in medicine and cancer research. However, I was wrong. I truly enjoyed this module, from TEM to making batteries, from brainstorming research ideas to presenting our research proposal. It was my second time seeing TEM samples, but it was just as fascinating as the first time. The phage nanowires were intertwined with evenly distributed gold nanoparticles, and the gold atomic planes were so regular and amazingly beautiful. On the last day of Module 3, it was so exciting to see batteries being made, and to light up LEDs using batteries with the cathodes we made! The unimaginable beauty in the order, simplicity, and complexity of nature, from atoms to nanoparticles, from proteins to cells to organisms, is what drew me to biology in the...
Read more

Presentation

The presentation went well. I think it was super helpful to fake present to classmates and instructors. Getting feedback from people who didn't know very much about our topic was really important for overcoming the bias of information. That’s when you know more than your audience and because of this assume a certain level of literacy with your topic that your audience doesn’t necessarily have. We practiced a lot to different people and I think that paid off and turned a presentation that was initially inscrutable and complex to something that was logical and understandable. 
Read more

Mod 3 experience

I was initially worried after reading the introduction of Mod 3. I didn't necessarily understand what was going on at first and I did not want to work with batteries as I thought this was not what I signed up for. However, as time went on and we continued to learn what was going on, this was a really fun module. I genuinely enjoyed working on the lab, seeing the TEM results, and constructing our batteries. To think we can use our skills as biological engineers to make batteries is quite interesting. Also, the fact that the paper is roughly 3 papers makes it so much easier to do. Our presentations were also really interesting and I really like all of the ideas that I've heard from my peers. It really taught me that we're not that far away from writing our own papers in the future and coming up with ideas for research projects. Overall, 20.109 has equipped me with the essentials to be a biological engineer but most importantly, how to communicate with others in our field.
Read more