6.3.7 DNA Profiling

Question 1

What does DNA profiling let us do?

Answer 1

• Determine genetic identity of an organism forensically
• We can identify suspects from crime scenes and corpses
• Based off their unique VNTRs (everyone has different lengths, but numbers of VNTR regions are inherited from parents)

Question 2

What is the process of obtaining a DNA Profile?

Answer 2

1. Obtain DNA (from a root hair, blood, semen, saliva. Care must be taken to not contaminate samples)
2. Increase quantity of DNA by PCR
3. Use restriction endonucleases to cut close to VNTR sequences, (cutting amplified DNA molecules into fragments)
4. Separate fragments using gel electrophoresis
5. Add proves (radioactive or fluorescent) that are complementary to VNTR regions and bind to them
6. Image (using X ray or UV light) is produced, containing patterns of bars (the DNA profile) which is analysed

Question 3

Other applications of DNA profiling?

Answer 3

• Crime scenes
• Corpses
• Identifying VNTR sequences associated with high incidence of diseases
• Determining familial relationships for paternal cases (who is the father, migration patterns)
• Species conservation