This Is How We Do It ♫

Julianna Duran, Virginia Tech


First and foremost, if you didn’t get the reference in the title please click here!

Now that I have educated you on the topic of music, let’s switch to science.

 The Approach: In my previous post I mentioned that I am studying the lipids of Nile Crocodile and Mozambique Tilapia. So the first thing I did is wrestle the reptile like Steve Irwin and hand catch my fish – just kidding, but imagine how cool that would be! My samples were collected from Lake Loskop, South Africa in 2014. Once they were in my possession, here is what I did.

  1. Sample Preparation
    • The muscle tissue samples I received looked like chicken breasts you buy from the grocery store – except the size of a fat bean. These solid chunks need to be turned into a fine powder for me to analyze them. This was done by freezing the sample in the cryomill machine – where the samples were shaken extremely fast and broken up



  2. Extraction
    • Think of what happens when you pour oil in water. They go to different ends and don’t mix, right? (Yes) That is exactly what I’m doing with my samples. We are adding lots of chemicals to break down fats into their building blocks: Fatty Acids! The muscle layer (organic layer) hates touching the chemicals, so I take that out and can use it for my next step!
    • Check out a video I made of one of my extractions
  3. Gas Chromatography
    • This instrument is how I will measure the amount of each fatty acid in my samples.
    • How does it work?
      • The sample is injected into the system and enters a narrow glass column. The sample separates in this column based on its weight and boiling point. The particle encounters a flame at the end of the glass, which detects what specific fatty acid it is. The computer then gets this signal and generates a graph showing a fatty acid profile. Each peak on the graph is a different fatty acid, and the height of the peak indicates how much of it there is in the sample.
      • For help envisioning this process, take a look at this video (I used it when I learned about this instrument!)




I will be physically and chemically breaking down my samples, then getting fatty acid profiles for each of my individual species. This is all to see if there is a difference between healthy and diseased species and what lipids are most affected by Pansteatitis!

Supported by the Fort Johnson REU Program (NSF DBI-1757899), Dr. Mike Napolitano, Dr. John Bowden, The College of Charleston, NOAA, and NIST. 


CryoMill. (accessed Jun 18, 2019).