Note: This month's "Scientist's Pick" is from Science Buddies' staff scientist, Sandra Slutz. ~ Science Buddies' Editorial Staff
Project: Forensic Science: Building Your Own Tool for Identifying DNA
Scientist: Sandra Slutz
Science Buddies' Difficulty Level: 7-9
Sometimes, when I'm supposed to be sitting down and concentrating on a task, my mind wanders. You never know what will come of those momentary mental strolls. In this case, the result was a pretty cool Do-It-Yourself project to build one of the very basic tools used in a biotechnology lab: an electrophoresis chamber.
I was supposed to be working on a science project called Investigate Native Plant Evolution with Chloroplast Sequencing. The project shows students how to harvest plants indigenous to the area in which they live, extract DNA from the plants, and then sequence the DNA. Then (drum roll for the really awesome part) if the sequence is new, meaning if no one has ever recorded that information before, they can submit the data to GenBank — the public gene sequence data bank — for scientists worldwide to see and use!
The only downside to the project is that it requires access to some specific biotechnology equipment. As I started to write down the list of materials and equipment that the project calls for, I asked myself, "Hey, I wonder if you can build any of this stuff yourself?"
From there my mind went racing through a list of possibilities. What I finally settled on was an electrophoresis chamber, the fancy title for a box that you pass current through to separate DNA into different size pieces and get a look at those pieces. The electrophoresis chamber is one of the most common pieces of equipment in any biotech laboratory. Why? There are literally dozens of reasons, but here's an example:
Imagine you are working in a forensics lab trying to determine if the hair left at a crime scene belongs to any of the suspects. How would you do it? You would isolate DNA from the crime scene hair and some DNA from each suspect. Then you'd cut up each DNA sample using enzymes. When you cut the DNA this way, each person has his or her own unique pattern of pieces (similar to the way each person has a unique fingerprint—in fact the DNA pattern is referred to as a DNA fingerprint). To look at the DNA pattern, you would use an electrophoresis chamber. If one of the suspects' DNA pattern matched the crime scene hair's pattern, you'd be able to place that suspect at the scene of the crime.
As you can see, the electrophoresis chamber is an important tool for forensics research!
It turns out you can make a simple version of an electrophoresis chamber on your own kitchen counter using just a few household items like batteries, a plastic soap dish, some stainless steel wire, and baking soda.
Once you've built your electrophoresis chamber, you have lots of options for putting it to use. Don't feel up to processing DNA on your home-made electrophoresis chamber? No problem! You can use the same equipment to examine food dyes. Did you know that some of the primary colors (like red) in food dyes are actually blends of several colors? Can you guess which colors? Give it a try! You might just find yourself hooked on the power of kitchen biotech.
For similar project ideas, explore the Biotechnology interest area, sponsored by Bio-Rad, in the Science Buddies Project Directory.
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