DNA Forensics and Color Pigments
Students perform DNA forensics using food coloring to enhance their understanding of DNA fingerprinting, restriction enzymes, genotyping and DNA gel electrophoresis. They place small drops of different food coloring ("water-based paint") on strips of filter paper and then place one paper strip end in water. As water travels along the paper strips, students observe the pigments that compose the paint decompose into their color components. This is an example of the chromatography concept applied to DNA forensics, with the pigments in the paint that define the color being analogous to DNA fragments of different lengths.
DNA analysis as an alternate "fingerprint."Copyright Cold Spring Harbor Laboratory http://summercamps.dnalc.org/info/forensics.html
Microfluidics concepts and devices used to study colloidal particle flow are also employed by biologist to study and filter biomolecules. Gel electrophoresis is one example of the many and creative engineering applications that are used by biologists to compare fragments of DNA samples.
After this activity, students should be able to:
- Describe the basic steps involved in DNA fingerprinting.
- Explain the function of restriction enzymes and the role of restriction sites along the DNA.
- Explain how DNA fragments are charged molecules.
- Explain that the distance traveled by DNA fragments inside a gel tray depends on fragment.
- Explain that the DNA (genetic code) from related organisms contain similar restriction sites and related DNA are cut into similar fragments by the same restrictions enzymes.