Use gel electrophoresis to compare DNA fingerprints from the shark attacks and determine if a single shark is to blame.

• Techniques: Micropipetting, gel electrophoresis
• Topics: Forensics, genetic polymorphism, environmental science, biotechnology
• Time required: Can be completed in one 45-minute class period
• Level: Advanced high school through general high school

Help marine biologists understand the source of shark attacks that are frightening Australian beachgoers! This guided-inquiry activity exposes students to the fundamental principles of DNA fingerprinting, which is routinely used to identify individuals based on their genetic makeup. DNA fingerprinting has a broad range of human applications, including forensics and paternity testing, but it is also an important tool in ecology. Students will determine if a single shark has attacked multiple times or if there are several different attackers.

Reagents and consumables supplied by user:
- Agarose (electrophoresis grade)
- DNA stain (e.g., GelGreen™)
- Gel electrophoresis buffer (e.g., 1X TBE)
- Distilled or deionized H₂O (to dilute buffer concentrate – not included in Lab Companion Kit)
- Microtubes

Required equipment:
- Micropipettes and tips
- Gel electrophoresis and fluorescence visualization system

Storage notes:
- Reagents require freezer storage
- Reagents are stable for 12 months when stored in the freezer