Background Information

Activities

General Outline

  1. Prepare the gels first and get them ready for loading prior to anything else to ensure there is adequate time for analysis
    1. Place gaskets at end of casting tray
    2. Place comb at the NEGATIVE side of the casting tray
    3. Add 60ml TBE buffer to a flask with 0.6 g agarose
    4. Microwave solution for 1 minute while watching to avoid boil-over
    5. Stop from boil-over and swirl solution with gloved or mitted hand
    6. Continue microwaving if not completely molten
    7. You should add 6μl of SYBR safe into your gel and swirl using the the variable pipettor
      • DO NOT use all the dye since it should last the entire day
    8. Place casting tray in refrigerator and pour the solution into tray
  2. Provide a short review of the previous activities with the dyes and the analogy to DNA migration/analysis
  3. Introduce the idea of PCR (Structure & Function, Information Flow, Systems, Quantitative Reasoning, Integration of Systems)
    1. Continue to describe reverse complementarity of DNA
    2. Describe the significance of PRIMERS in directing the synthesis of DNA molecules
    3. The exponential nature of PCR and doubling
  4. Run the gel
    1. When gels are cooled and firm, gently wiggle the gaskets off ends to avoid tearing gel
      • This is very important this week since the combs are near the gasket
    2. Place casting tray with gel into electrophoresis tank and ensure gel is covered with buffer (or add additional buffer)
    3. Demonstrate loading the forensics samples
      • These are not human DNA but are digested phage DNA
    4. They are Crime Scene (Enzyme 1), Crime Scene (Enzyme 2), Suspect 1 (Enzyme 1), Suspect 1 (Enzyme 2), Suspect 2 (Enzyme 1), Suspect 2 (Enzyme 2)
    5. Ensure you have at least 45 minutes to run at 110V and review gels on transilluminator
  5. Introduce the concept of CODIS and modern forensics using VNTRs and STRs (Structure & Function, Information Flow, Systems, Quantitative Reasoning, Integration of Systems, Science & Society)
  6. Review the results of the gels on the transilluminator
    1. CAUTION with the UV transilluminators
    2. Have the students document the gels with their cameras
    3. Review the results and decide who was at the scene of the crime and requires further investigation

Curricular Notes

This unit covers the NSF Vision & Change Core Competencies:

  1. Quantitative Reasoning: doubling and exponential nature of replication
  2. Integration of Systems: electrophoresis and genome diversity
  3. Science & Society: forensics
  4. Interdisciplinary Nature of Science: RFLPs/VNTRs and forensics, electrophoresis
  5. (Visual) Communication: review of gels

This unit covers the NSF Vision & Change Core Concepts:

  1. Structure & Function: DNA base complementarity
  2. Information Flow: DNA replication
  3. Systems: integration of genome diversity
  4. Evolution: diversity of genomes

This unit covers additional General Education competency:

  1. Life-long Learning
Return to Course Coordination
Print this page