Pre-Lab: Using DNA to Solve Crimes
Problem How can DNA samples be used to connect a suspect to a crime scene?
Materials gel block, electrophoresis chamber, buffer solution, 250-mL beaker, metric ruler, DNA samples, micropipettes, 9-volt batteries, electric cords, staining tray, DNA stain, 100-mL graduated cylinder, clock or timer
Lab Manual Chapter 15 Lab
Skills Focus Measure, Compare and Contrast, Draw Conclusions
Connect to the Scientists who worked on the Human Genome Project had to develop methods for sequencing and identifying genes. Those methods have since been used for many other applications. For example, genetically altered bacteria are used to produce large amounts of life-saving drugs. Another example is the use of DNA evidence to solve crimes. In this lab, you will prepare and compare DNA “fingerprints,” or profiles.
Review What characteristic of the human genome makes DNA a powerful tool for solving crimes?
Review What do the segments of DNA that are used to make DNA profiles have in common?
Apply Concepts When forensic scientists want to determine whether two DNA samples come from the same person, they analyze more than one section of DNA. Why would the results be less reliable if the scientists compared only one section of DNA?
Preview the procedure in the lab manual.
Control Variables Why must you use a new pipette to load each DNA sample?
Relate Cause and Effect Why will the DNA samples separate into bands as they move through the gel?
Infer Why is purple tracking dye added to the DNA samples?
Visit Chapter 15 online to test yourself on chapter content and to find activities to help you learn.
Untamed Science Video Pigeon breeding helps the Untamed Science crew unravel the mysteries of genetic engineering.
Art in Motion View a short animation that brings bacterial transformation to life.
Art Review Review your understanding of DNA fingerprinting with this drag-and-drop activity.
Data Analysis Analyze nutrition and genetic data on nutrient deficiencies and crops genetically engineered to improve nutrition.