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Non-STR DNA Markers: SNPs, Y-STRs, LCN and mtDNA

LCN Methodologies

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Various strategies have been developed in the scientific community to deal with low template DNA samples, however, LCN (Low Copy Number) gained the most traction.  

A standard PCR uses 28-30 cycles. In order to improve sensitivity for LCN analysis, an increase in PCR cycle number to 34 is used.  This six-fold increase in cycle number would be expected to produce a theoretical 26 fold increase in sensitivity (i.e., 64) but inefficiencies with the PCR process at later cycles reduces this significantly.  Nevertheless LCN will result in increased sensitivity with the concomitant production of stochastic sampling artifacts and, in some cases, the detection of otherwise-undetectable, extraneous DNA contamination.

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