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Scientific Issues with Analysis of Low Amounts of DNA



John Butler, Becky Steffen


Faced with limited evidence that yield low amounts of DNA, forensic analysts will continually have to confront the question of how far to push DNA testing techniques. Low copy number (LCN) analysis, also known as low template DNA (LT-DNA) testing, involves enhancing detection sensitivity usually through increasing the number of PCR cycles. Stochastic effects inherent with analysis of low amounts of DNA yield allele or locus drop-out. Additionally, increasing detection sensitivity can result in a greater potential for contamination or allele drop-in. Validation studies with replicate testing of low amounts of DNA were performed to assess the level of allele and locus drop-out and allele drop-in using 10, 30, and 100 picograms (pg) with several commercially available STR typing kits under both standard and increased number of PCR cycles. The results with pristine fully heterozygous samples demonstrate that a replicate testing approach can produce reliable information with single-source samples when consensus profiles are created.
profiles in DNA


consensus profiles, low copy number, LCN, low template DNA, LT-DNA, replicate testing


Butler, J. and Steffen, B. (2010), Scientific Issues with Analysis of Low Amounts of DNA, profiles in DNA, [online], (Accessed July 17, 2024)


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Created September 7, 2010, Updated March 26, 2024