Genetic fingerprinting

Genetic Fingerprinting (also called DNA testing, DNA typing, or DNA profiling) is a technique used to distinguish between individuals of the same species using only samples of their DNA. Although two individuals will have the vast majority of their DNA sequence in common, DNA profiling exploits highly variable repeat sequences called VNTRs. These loci are variable enough that two unrelated humans are unlikely to have the same alleles. The technique was first reported in 1984 by Dr. Alec Jeffreys at the University of Leicester, and is now the basis of several national DNA identification databases.

Reference samples

DNA identification must be done by an extraction of DNA from substances such as:

• Personal items (e.g. toothbrush, razor, ...)
• Banked samples (e.g. banked sperm or biopsy tissue)
• Blood kin (biological relative)
• Human remains previously identified

Reference samples are often collected using buccal swab.

Variations of VNTR allele lengths in 6 individuals.


http://images.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/en/thumb/2/23/Phylogenetic-Groups.svg/400px-Phylogenetic-Groups.svg.png&imgrefurl=http://tech1207.blogspot.com/2007_12_28_archive.html&h=341&w=400&sz=38&hl=en&start=10&um=1&tbnid