A crime has occurred in your classroom!
- Techniques: Micropipetting, DNA extraction, PCR, gel electrophoresis
- Topics: forensics, genetic polymorphism, biotechnology
- Time required: Can be completed in two 45-minute class periods or one 90-minute class period
- Level: General high school through college
Students will use PCR to amplify their own DNA and compare it to a sample obtained from a hypothetical crime scene to try to rule themselves out as a suspect. Variable number tandem repeats (VNTRs) are regions in a genome that contain short stretches of DNA repeated a number of times. The number of repeats in a particular VNTR can vary from individual to individual. In this way, genetic variation in VNTRs can be used as markers for personal identification. This hands-on activity lets students explore molecular biology in personal identification and forensics, as well as inheritance, human genetics, DNA polymorphisms, and genetic diversity.
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
- PCR tubes
Required equipment:
- Micropipettes and tips
- Thermal cycler
- Gel electrophoresis and visualization system
Storage notes:
- Reagents require freezer storage
- Reagents are stable for 12 months when stored in the freezer
Accessories information: The learning lab companion kit (catalog no. 470352-026) contains all the consumables (except water) needed for a class of 32 students. These reagents and consumables can also be sourced independently.
Delivery information: The miniPCR Forensics Lab kit contains reagents for 8 lab groups of 4 students each (32 students): X-Tract™ DNA extraction buffer (2 vials); 2X Blue PCR Master Mix, Load-Ready™; D1S80 Lab Primer Mix; “Crime Scene” DNA control sample; 100 bp DNA Ladder, Load Ready™. Note: Reagents are compatible with blueGel™ or other standard horizontal electrophoresis systems.
