Mini-Barcode
Definition
A short DNA barcode amplicon (typically 100-250 bp) designed for use when template DNA is fragmented by drying, heat, or age. Standard COI and cytochrome b barcodes (600-700 bp) often fail on degraded fin tissue; mini-barcodes are more reliably amplified.
- Amplicon length
- About 100 to 250 bp
- Standard barcode length
- 600 to 700 bp (COI, cytochrome b)
- Use case
- Dried, heat-treated, or otherwise degraded tissue
- Field
- Shark and ray product identification
Common questions
Why does a shorter amplicon succeed where the full barcode fails?+
Degraded DNA breaks into progressively shorter fragments, and PCR can only amplify a target if an intact stretch of that length survives; a shorter mini-barcode target has a much higher chance of finding an unbroken template than a 600 to 700 bp region.
Does shortening the barcode reduce its species-identification power?+
It reduces the amount of sequence available for comparison, which can occasionally limit discrimination between very closely related species, but validated mini-barcode regions are chosen specifically because they retain enough variable sites to identify species reliably despite the shorter length.
Related terms
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- Elasmobranch
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- Fin Spine
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- Vertebral Age Rings
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