DNA Profiling

Uses of DNA profiling

Paternity tests

Forensics

Assessing disease risk

Classification/species identification

Introns

Non-coding regions of the DNA

Explain why some regions of DNA can be described as non-coding

These regions are not present in mature mRNA and are not translated

Suggest why non coding regions of DNA show more variation

They aren’t selected against. They don’t affect survival.

Why do we use introns for genetic profiles?

- In most people, the genome is very similar

- Using coding sequences of DNA would not provide unique profiles

- Introns contain repeating sequences

STRs

Short tandem repeats

2-4 base pairs repeated 5-15 times

VNTRs

Variable number tandem repeats

20-50 base pairs repeated from 50 to several 100 times

What is the name for the sequence of bases that is repeated in Short tandem repeats (STRs) and variable number tandem repeats (VNTRs)?

The core sequence

1) DNA Profiling

Extract the DNA

2) DNA Profiling

Amplify the DNA fragment with PCR

3) DNA Profiling

Cut the DNA with restriction enzymes

4) DNA Profiling

Separate DNA fragments using electrophoresis. The DNA will be separated based on their mass.

5) DNA Profiling

Transfer fragments to paper

6) DNA Profiling

Apply a radioactive probe.

Use x-rays to view the position of DNA fragments

7) DNA Profiling

As a result, you create genetic profiles, which can be used in paternity tests, forensics, and for analysis of disease risk.