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DNA Extraction and Quantitation for Forensic Analysts


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Chelex® 100 Extraction Process - Non-differential
National Institute of Justice (NIJ) (see reuse policy).

Chelex® 100 extraction methods are straightforward, with little variation between procedures. Some examples are:

  • Laboratories may differ with respect to their inclusion of Proteinase K, a serine protease that aids in protein digestion.
  • For extraction from blood, the sample may be incubated in sterile deionized water that promotes hemolysis of red blood cells. This aids in the removal of heme, a known PCR inhibitor.
  • Some laboratories wash the sample in phosphate buffered saline prior to extraction. The sample may be washed one or more times and pelleted through centrifugation before resuspending it to carry out the Chelex® 100 extraction procedure.

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