STR Profiling
Definition
Short tandem repeat profiling: the same multi-locus PCR-based method used for human identity testing, adapted for target species with species-specific primer sets. Generates an individual genetic profile that can match a seized product to a specific animal in a reference database, such as a national rhinoceros horn registry.
- Type of DNA analysis
- Measures short tandem repeat sequences at multiple chromosomal locations
- Primary output
- A numerical profile that can be compared against reference samples or national databases
- Status in forensic labs
- The dominant DNA typing method in forensic laboratories
Common questions
What does STR profiling actually measure?+
STR profiling counts the number of repeated DNA sequences at specific locations along your chromosomes. These repeats vary in length between individuals, creating a numerical profile that acts like a genetic fingerprint.
How is STR profiling used to match evidence?+
The numerical profile from evidence at a crime scene is compared against reference samples (such as from a suspect) or national DNA databases. If the profiles match across multiple loci, it indicates the samples came from the same person.
Is STR profiling only used on humans?+
No. The same DNA fingerprinting technology is applied to wildlife for species identification and individual matching. Rhinoceros horn forensics, for example, uses STR profiling to generate individual-specific profiles for database entry and evidence matching.
Related terms
- Ante-Mortem Data (AM)
- Information about a person recorded before death: dental charts, medical records, photographs, physical descriptions, fingerprints, and DNA reference samples from biological relatives....
- Chain of Custody
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- CITES Appendix
- CITES classifies listed species into three appendices. Appendix I prohibits commercial trade; Appendix II permits trade only with documented permits and quota...
- Cytochrome B (Cyt B)
- A mitochondrial protein-coding gene widely used in forensic species identification before COI barcoding was standardised. Still used because its reference database for...
- DNA Barcoding
- Species identification using a short, standardised region of the mitochondrial genome. For animals, the primary barcode marker is a 648-base-pair segment of...
- Fire Debris Analysis
- The laboratory examination of material collected from a suspected arson scene to detect and identify accelerants (hydrocarbons from petrol, lighter fluid, or...
- GC-MS
- Gas chromatography-mass spectrometry: a two-stage technique that separates the components of a mixture (GC) and then identifies each component by its molecular...
- Hair-Shaft Tubules
- Microscopic cylindrical structures running along the length of the horn, structurally analogous to hair follicles. Their diameter, packing density, and internal structure...
- INTERPOL DVI Forms
- Standardised yellow (AM) and pink (PM) forms developed by INTERPOL for recording ante-mortem and post-mortem data in a comparable structure. Used across...
- Keratin
- The structural protein that forms pangolin scales, human fingernails, and bird feathers. In scales it is arranged in a layered matrix whose...
- Likelihood Ratio (LR)
- The ratio of two conditional probabilities: the probability of the observed evidence given the prosecution's hypothesis (same source), divided by the probability...
- Minimum Number of Individuals (MNI)
- The smallest number of distinct individuals required to account for all skeletal elements present in an assemblage. Determined by identifying the element...
Explained in these topics
- Ante-mortem Data Collection and Victim IdentificationShort tandem repeat profiling: the standard forensic DNA method that measures the length of repetitive sequences at multiple chromosomal locations. Produces a...
- The Core Lab Sciences: Biology, Chemistry, PhysicsShort tandem repeat profiling, the dominant DNA typing method in forensic laboratories. It measures the number of repeated sequences at multiple specific locat...
- Rhinoceros Horn ForensicsShort tandem repeat profiling, the same DNA fingerprinting technology used in human forensics, applied to rhinoceros to generate individual-specific profiles f...
- Wildlife Crime and Biological EvidenceShort tandem repeat profiling: the same multi-locus PCR-based method used for human identity testing, adapted for target species with species-specific primer s...