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Forensic DNA

From ISOGG Wiki

For a good introduction to the use of DNA in criminal investigations read the guide from Sense About Science on Making Sense of Forensic Genetics.

Forensic STR analysis

Short tandem repeat (STR) analysis is a relatively new technology in the field of forensics, having come into popularity in the mid-to-late 1990s. It is used for the genetic fingerprinting of individuals. STRs are extracted from autosomal DNA, DNA which is inherited from both parents. Autosomal STRs can, therefore, be used to identify both males and females.

In the United States, 13 core autosomal STR loci (markers) have been selected as the basis by which an individual genetic profile can be generated. These profiles are stored at a local, state and national level in DNA databanks such as CODIS. The United Kingdom database for STR loci identification is the UK National DNA Database (NDNAD). In Europe the DNA17 test is used. This test uses 16 autosomal STRs and a gender marker.[1] The UK National DNA Database was upgraded with effect from July 2014 to take account of the new test.

Note that the DNA tests used in surname DNA projects look at Y-chromosome STRs (Y-STRs). The autosomal STRs used for forensic analysis identify one person in a million. In contrast Y-STR signatures are shared by many people with the same surname and do not identify an individual. The autosomal DNA tests used by genetic genealogists look at autosomal SNPs (single nucleotide polymorphisms and not autosomal STRs.

Forensic DNA databases

Scientific papers

News stories

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Useful links



  1. DNA 17 – The New DNA Profiling Standard. Forensic Access website, August 2014.