Nerd moment #937: Gel Electrophoresis and DNA Fingerprinting

Multiple questions come up whenever I tell people I’m a bio major. “Are you crazy?” “What do you plan to do with that degree?” “Why did you choose that major when you started out as an art major?”

The answers to those questions are, respectively, and in the simplest forms: yes, save the world, and because we get to do cool stuff like this:



That, guys and gals, is how to catch a killer.

That blue blob is the result of gel electrophoresis, which is just a fancy way of saying we made a Jell-O-like substance, put DNA samples in it, and shocked it for almost two hours. You can get one of these kits on any science-y type website to try it at home, and you pretty much do it in any biology class in college. I myself have done three electrophoreses in the past year.

The point of this fancy-schmancy blob is really to demonstrate how very unique DNA is and how it gets broken down by restriction enzymes to show that your DNA does not match someone else’s DNA, but they tell all the uninterested college kids that what we’re really doing is looking at two samples from a crime scene and trying to match it up to one of two suspects. That way, we can all fulfill our lifelong dreams of reenacting the show CSI: Miami. Except for the fact that this is ten times cooler because half the things they do on CSI: Miami aren’t real and this is a true way that forensics labs really roll.

I won’t get into the extreme details of it, but at a basic level, you add enzyme to DNA and it breaks it into smaller fragments, which are represented by the separate blue stripes in the picture. If you have a suspect DNA that has the same exact bands as the evidence DNA, you can say you’ve found yourself a criminal and call it a day.

There are a lot of downsides to using this type of DNA fingerprinting, as well as a lot of room for human error. For instance, the way we ran our lab made it so accuracy was key, and let’s just say college kids have no accuracy at 8 A.M. This is the case with any electrophoreses however, whether the FBI or DU students run this experiment.

So why did I choose biology? Why did I primarily want to go into forensics or genetics? Things like that blue blob, that’s why. I mean, how cool is that? Or is my nerdy college-kid swag just going crazy there?

What do you want to do and why? If you’re a college kid, why did you choose your major? Have you ever wanted to be on CSI: Miami?