- 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
Other STR Loci
Home > DNA Amplification > Locus Selection > Other STR Loci
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There are some differences between the international community and the U.S. regarding which STR loci are used. Nevertheless, there are sufficient common loci to permit the sharing of meaningful profile information.
The United Kingdom (U.K.) pioneered forensic DNA testing with programs that began more than 20 years ago. The Forensic Science Service (FSS) began STR testing in 1994 with the Quadruplex system, which consisted of vWA, THO1, FES, and F13A1. This kit was manufactured in-house at the FSS but was not very discriminating. The FSS quickly replaced it with the AmplFSTR® SGM™ (Second Generation Multiplex) kit. This kit consisted of six STR loci (D8S1179, THO1, vWA, D21S11, FGA, and D18S51) and amelogenin, with an estimated discriminating power of 1 in 50 million.03, 04
Click here to visit the Forensic Science Service's website.
The AmplFSTR® SGM™ provided the core loci used when the U.K. established its National DNA Database in 1995. Further STR/database developments included the extension of the six STR loci used for crime stain analysis in 1996 and the subsequent adoption of the six STR loci by ENSFI.05
As the number of samples in the database increased to well over a million, the chances of a coincidental match between unrelated individuals became too great, as was illustrated in a 1999 case. A man with advanced Parkinson’s disease, (unable to drive a car or dress himself without assistance) was linked to a burglary that occurred a great distance from his home. After he was arrested, it was apparent that his physical condition would have made it impossible for him to have committed the crime.
Researchers were already evaluating the possibility of adding more STR loci to the core group and their work resulted in the introduction of AmplFSTR® SGM Plus™. The kit contains the same loci as the AmplFSTR® SGM™ kit together with D3S1358, D19S433, D16S539, and D2S1338. The four additional loci increase the discriminating power to 1 in 33 trillion. Retesting the case samples with the additional loci subsequently exonerated the man.06
Across Europe, ENFSI (through the European DNA Profiling Group, or EDNAP) decided on the use of seven common loci for their core STRs:
- D3S1358
- TH01
- D21S11
- D18S51
- vWA
- D8S1179
- FGA
Recently, ENFSI and EDNAP have increased the core loci to include:
- D10S1248
- D14S1434
- D22S104507
The addition of core loci has been implemented in anticipation of a significant increase in the size of the database. The International Criminal Police Organization (INTERPOL) has adopted the core European loci, enabling governments within Europe to compare samples across countries.
Click here to visit INTERPOL's website.
