Gene Tech - Genetic Fingerprinting

Question 1

What are VTNRs?

Answer 1

Variable Number Tandom Repeats

- Sequences that don’t code for proteins and are repeated.

Question 2

How is a genetic fingerprint made?

Answer 2

1) Obtain a DNA sample
2) Use PCR to make copies
3) Cut into fragments using restriction endonuclease
4) Fragments are separated according to size using gel electrophoresis
5) Then transferred to nylon membrane
6) DNA probes are added to label specific fragments to be identified

Question 3

What is gel electrophoresis?

Answer 3

Separates DNA fragments by size:
- Fragments are placed onto an agar gel and an electrical current is passed through.
- Larger the fragments, the slower they move.
Therefore smaller fragments move further in a fixed time.
- They can be tracked using probes