Genetic Fingerprinting

VNTRs

Variable number tandem repeats

type of DNA which mutates the most

introns (non coding regions)

how vntrs allow people to be identified

probability of two individuals having the same VNTR's is very low

how DNA fragments are made for GF

using a PCR

uses of genetic fingerprinting

Forensic science

medical diagnosis

Animal and plant breeding

why endonucleases are used

to cut large strands of DNA into fragments

how DNA is separated

using gel electrophoresis

how gel electrophoresis separates DNA

DNA has a negative charge

smaller fragments move further than larger fragments

how DNA fragments are transferred from gel to nylon membrane

southern blotting

Hybridisation

DNA probes added to label the fragments.

how genetic fingerprinting is developed from nylon sheet

x-ray film reveals dark bands where probes have attached