Food Truck Trouble! Solve a Real-World Food Safety Mystery in Your Classroom

Why we wrote this new Food Safety Lab scenario:

This real-world scenario transforms students into public health investigators.

• Engaging storyline: Students work for the Department of Public Health, investigating a serious foodborne illness outbreak.
• Real-world application: Students learn to differentiate between pathogenic and non-pathogenic bacterial strains, focusing on the toxin-producing E. coli O157:H7.
• Essential molecular biology skills: Students will gain hands-on experience with crucial techniques:
  • Micropipetting
  • Polymerase Chain Reaction (PCR)
  • Restriction Digestion
  • Gel Electrophoresis
• Critical thinking: The lab promotes scientific inquiry, data analysis of multiple kinds, and evidence-based reasoning.

The science behind the solution: DNA restriction fragment length differences

Students will use a powerful sequence of molecular techniques to pinpoint the contamination source:

1. PCR: They’ll amplify a 400 base pair E. coli DNA segment that differs between pathogenic and non-pathogenic strains. The template DNA is provided in the kit, and the PCR product is stable for days, offering scheduling flexibility.
2. Restriction digestion: The restriction enzyme XmnI cuts the PCR product only if pathogenic E. coli O157:H7 DNA is present. Non-pathogenic DNA remains uncut. While overnight incubation is recommended, results are still conclusive with a minimum of 15 minutes to fit into shorter class periods.
3. Gel electrophoresis: Students then visualize the DNA fragments. Pathogenic E. coli O157:H7 will show two bands (250 bp and 150 bp) due to the cut, while non-pathogenic E. coli will show a single 400 bp band. By comparing food samples to control samples, the contamination source is revealed.

Teacher-friendly and fully supported

Designed with educators in mind, this lab offers:

• Flexible timing: Complete it in a single 2.5-hour class or spread it across multiple 40-min sessions.
• Reduced prep: Many teacher prep steps, like gel preparation and reagent dispensing, can be done up to a week in advance, saving valuable class time. The kit even recommends diluting the restriction enzyme for ease of pipetting.
• Safe but authentic: All DNA samples are synthetic and non-pathogenic, ensuring safety while providing an authentic scientific experience.
• Comprehensive resources: Includes detailed Instructor and Student Guides, e-worksheets, video tutorials for key techniques (micropipetting, PCR, gel electrophoresis), and alignment to standards like NGSS, TEKS, and others.
• Dedicated technical support: Questions? Just contact support@minipcr.com.

What you’ll need:

The Food Safety Lab kit (KT-1001-04) provides reagents for eight lab groups, including simulated DNA samples, Master Mix, Primer Mix, Restriction Enzyme, Nuclease Free Water, and Fast DNA Ladder 2.

You’ll need to supply:

• 2% agarose gels with fluorescent DNA stain (e.g., SeeGreen™ or GelGreen®).
• Plastic tubes (PCR and reagent distribution).
• A thermal cycler (e.g., miniPCR thermal cycler).
• A gel electrophoresis and visualization system (e.g., blueGel™ or Bandit™ systems with blue light transilluminator).
• Micropipettes and tips.
• Basic lab supplies like gloves, eyewear, markers, distilled water, and a microwave/hot plate.

Equip your students to be real-world scientific investigators. Bring the “Food Safety Lab: Food Truck Trouble!” into your classroom and empower them to solve the mystery!