Alu PCR: 11% of the Genome, Revealed!
This unit introduces students to PCR, issues of identity, and issues of privacy. Students isolate their cheek cell DNA from a saline mouthwash. They amplify a SINE (Short Interspersed Nuclear Element) with the polymerase chain reaction procedure, using pre-made master and primer mixes. Maintaining sample privacy, students electrophorese their reactions, stain and photograph their gels, and analyze their Alu genotype. Anonymously, data can be entered into the Allele Server database at Cold Spring Harbor’s DNA Learning Center
Follow-up activities include determining whether the class is in Hardy-Weinberg Equilibrium and plotting the “+” allele frequencies on a world map. Students compare their demographics to a map of global Alu distribution and brainstorm explanations for the original insertion of this particular Alu element in the human genome.
Beginner to Intermediate: This lesson is a good introduction to PCR and one of its uses, genotyping. It has several stopping points so there is flexibility in how the teacher wants to approach this lesson. It is appropriate for any biology or biotechnology class.