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DNA Amplification for Forensic Analysts

Locus Selection

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Short Tandem Repeats (STRs)
National Institute of Justice (see reuse policy).

There have been several technological developments since DNA testing was introduced into forensic science laboratories in the United States during the late 1980s. The historical developments are described in Crime Scene and DNA Basics for Forensic Analysts. The current technology is short tandem repeat (STR) analysis using the polymerase chain reaction (PCR).

The Human Genome Project has shown that there are tens of thousands of STR loci in human DNA. The selection of specific loci from the many available for use in forensic science laboratories is important for many reasons, but primarily to ensure that:

  • The loci have a high discriminating power.
  • The loci are stable in evidence samples.
  • There is a consensus panel of core loci for use in DNA databases.

Author: Russell Vossbrink

Russell Vossbrink is the technical supervisor of the Regional FBI mtDNA lab at the Arizona Department of Public Safety.  Russell is a member of the American Academy of Forensic Sciences (AAFS) and he has been a regular member and invited guest of the Scientific Working Group for DNA Analysis Methods (SWGDAM).  Russell has presented at Promega, Combined DNA Index System (CODIS), AAFS, California Association of Criminalists (CAC), Southwestern Association of Forensic Scientists (SWAFS), California Association of Crime Laboratory Directors (CACLD) and the Bode Technology Workshop.

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