- Course Introduction
- 01: Evidence & DNA
- 02: Forensic Biology
- 03: DNA Extraction & Quantitation
- 04: DNA Amplification
- Overview
- Introduction
- Amplification
- Primer Design
- Primer Length
- Primer Melting Temperature
- Primer Annealing Temperature
- Values for Tm
- Maximum 3′ Stability
- GC Content Percentage
- No Secondary Structures
- No Self-complementarity
- No Complementarity To Other Primers
- No Long Runs With The Same Base
- Distance Between Two Primers On Target Sequence
- Plateau Effect
- Thermal Cyclers
- Thermal Cycling Parameter and Optimization
- Works Cited & Online Links
- Locus Selection
- Multiplexing
- Contamination
- Overview
- 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
Deoxynucleotide Triphosphates (dNTPs)
Home > DNA Amplification > Overview > Thermal Cyclers > Deoxynucleotide Triphosphates (dNTPs)
The four dNTPs should be used at equivalent concentrations to minimize mis-incorporation errors. Lower dNTP concentrations minimize the mis-pairing at non-target sites and reduce the likelihood of extending mis-incorporated nucleotides.
Mis-incorporated bases cannot be proofread since Taq lacks a 3′ to 5′ exonuclease activity and mismatched bases are inefficiently extended. Mis-incorporation errors that do occur during PCR promote chain termination. Chain termination restricts the amplification of defective molecules and helps to maintain fidelity.
Stock dNTP solutions are generally neutralized to a pH 7.0. The stability of dNTPs during repeated cycles of PCR is such that approximately 50% of the dNTPs remain after 50 cycles.11 The concentration is usually between 20 and 200µM each.
