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BOLD Systems

Definition

Barcode of Life Data System (University of Guelph, Canada). Holds over 9 million COI reference barcodes linked to voucher specimens, with mandatory taxonomic verification. Primary reference for animal species identification.

Host institution
University of Guelph, Canada
Database size
Over 9 million COI reference barcodes
Primary marker
Mitochondrial COI (cytochrome oxidase I) sequences
Quality assurance
All sequences linked to voucher specimens with mandatory taxonomic verification

Common questions

What is BOLD Systems and why do wildlife forensics investigators use it?+

BOLD (Barcode of Life Data System) is a global repository of DNA barcode sequences hosted by the University of Guelph, Canada. It holds over 9 million reference barcodes linked to actual voucher specimens. Investigators use it to identify animal species found at crime scenes or in illegal wildlife trade by comparing unknown DNA sequences against the verified reference database.

How does a DNA barcode from BOLD help identify a species?+

A barcode is a short, standardized DNA sequence, usually the mitochondrial COI (cytochrome oxidase I) gene, that acts like a genetic fingerprint for a species. You extract DNA from an unknown sample, sequence the COI region, and search BOLD to find the closest matching reference. A match tells you what species you are looking at.

What makes BOLD reliable as a reference database?+

Every barcode in BOLD is linked to a voucher specimen that has been taxonomically verified by experts. This mandatory verification means the sequences are accurate and trustworthy. Because BOLD is curated and contains millions of validated sequences, it serves as the primary global standard for species-level DNA barcode matching in forensics.

Related terms

16S rRNA
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CITES Trade Database
Maintained by UNEP-WCMC, this holds records of all reported legal CITES-listed species trade. Used to detect permit fraud, unusual trade volumes, and...
COI (COX1)
Cytochrome-c oxidase subunit I gene. The 658-base-pair Folmer fragment is the globally adopted barcode-of-life marker for animals, curated in BOLD Systems and...
COI (Cytochrome C Oxidase Subunit I)
The 648 bp mitochondrial gene region proposed by Paul Hebert in 2003 as the universal barcode locus. Its combination of interspecific variation...
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 Barcode
A short, standardised sequence from a defined locus used to identify a specimen to species by comparison against a curated reference library....
ElePhant
A microsatellite (STR) reference database for African and Asian elephants, used to assign ivory seizures to continental and population-level origin.
ElePhant Database
A curated STR reference database for African savanna and forest elephants and Asian elephants, used to assign ivory to individual animals or...
ITS Region
Internal transcribed spacer region, flanking the 5.8S rRNA gene between the 18S and 28S subunits in fungi and plants. The ITS1-5.8S-ITS2 fragment...
Minibarcode
A 100-200 bp sub-region of the COI locus amplified when DNA is too degraded for the full 648 bp amplicon. Shorter target...
PCR-RFLP
PCR followed by restriction fragment length polymorphism analysis. A restriction enzyme cuts the amplicon at species-specific recognition sites; the resulting fragment pattern...
RhODIS
Rhino DNA Index System. A national STR database for rhinoceros individuals maintained at the Veterinary Genetics Laboratory, University of Pretoria. Used to...

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