- Course Introduction
- 01: Evidence & DNA
- 02: Forensic Biology
- 03: DNA Extraction & Quantitation
- 04: DNA Amplification
- 05: Amplified DNA Product Separation
- 06: STR Data Analysis & Interpretation
- 07: Population Genetics & Statistics
- 08: Communicating Results
- 09: Other DNA Markers & Technologies
- Course Resources
- Laboratory Training Manual
President's DNA Initiative
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Advancing Justice Through DNA Technology
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Advancing Justice Through DNA Technology
DNA Analyst Training
LCN Methodologies
Home > Other DNA Markers & Technologies > Other Nuclear DNA Markers and Technologies > Low Copy Number DNA > LCN Methodologies
Various strategies have been developed in the scientific community to deal with LCN samples including increased PCR cycle number (ICN), nested PCR and whole genome analysis.17, 18 Since the forensic community has adopted ICN as the standard LCN DNA approach, the other methodologies will not be considered here.
Increased Cycle Number (ICN)
A standard PCR uses 28-30 cycles. In order to improve sensitivity for LCN analysis, an increase in PCR cycle number to 34 is now standard. 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 ICN 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.
