Welcome to STEMinism Sunday! As a former woman in science, I have a deep and enduring interest in the experiences and representation of women in STEM fields (science, technology, engineering, and math). This series will be an opportunity for me – and you – to get to know some of these intellectual badasses.
Have you ever heard of Maud Leonora Menten? I hadn’t, until last week, when I read this fascinating post about her life and work. In 1911, she became the first Canadian woman to earn a medical degree. After completing her PhD, she went on to revolutionize the field of biochemistry. She made discoveries about enzymes that are fundamental to the field today. She was also the first person to use electrophoresis to isolate pure proteins from the mixtures that come from living things.
This last part is especially interesting to me, since I spent my entire PhD separating DNA fragments using electrophoresis. During electrophoresis, we load the substance we want to purify into a well, or slot, in a gel. DNA (like many proteins) is a molecule with an electrical charge. Since DNA is negatively charged, we connect a negative electrode to the well-end of the gel and a positive electrode to the far end. When we turn on the juice, the DNA is repelled by the negative electrode, and starts to migrate through the microscopic holes in the gel. Small pieces of DNA migrate more easily than long ones, so travel farthest through the gel. This is how DNA fingerprinting works, FYI. It’s also how Menten was able to separate proteins, but in that case, the process is slightly more complex, because different types of proteins carry electrical charges of different strength and polarities.
Want to know more about Menten’s work? Click on through to the Science Borealis blog for details. For more about DNA fingerprinting, book me for a forensics presentation at your school or library and get 10 free copies of Fuzzy Forensics!