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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.

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