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Amplified Fragment Length Polymorphism

Compare genomic samples through reproducibly selected, amplified restriction fragments scored as multilocus size-pattern differences.

Version
v1 · 2026-10-31 · History
Domain-specific #
14461

Core Idea

Amplified fragment length polymorphism (AFLP) compares genomic samples through a reproducibly selected subset of restriction-derived DNA fragments. Adaptors supply known priming regions at restriction-fragment ends; selective primer bases preferentially match flanking fragment sequences, reducing the subset amplified. Amplified fragments are resolved by apparent size and scored as a multilocus fingerprint. Variations in the profile can serve as anonymous markers without first knowing each sampled locus's sequence.[1]

How would you explain it like I'm…

DNA Barcode Patterns

Every living thing has a long secret code inside called DNA. Scientists can chop the code into lots of little pieces, copy only some of them, and line them up by size, making a pattern like a barcode. Comparing barcodes from two plants or animals shows where they are different. A matching stripe only means the pieces are the same size, not that they are surely the same piece.

DNA Fingerprint by Fragment Size

Amplified Fragment Length Polymorphism, or AFLP, is a way to compare the DNA of different living things. First, scientists cut the DNA into many pieces using special cutting chemicals and stick little known tags onto the ends. Then they copy only some of the pieces, chosen by a few letters next to the tags, and sort the copies by size into a pattern of bands. Comparing the band patterns of different samples shows where they differ. They don't need to know what each piece says beforehand. But two bands of the same size might come from different pieces, so a match isn't perfect proof.

Selective Fragment Fingerprinting

Amplified Fragment Length Polymorphism (AFLP) is a DNA fingerprinting method for comparing samples using many unnamed markers. Restriction enzymes cut the genome into fragments, short known sequences called adaptors are attached to the ends, and PCR copies the fragments using primers that match the adaptors plus a few extra 'selective' bases — so only a subset gets amplified. The copies are separated by size to form a profile, and differences between samples' profiles count as evidence of genetic variation (polymorphism). Its strength is that you don't need to know any of the sequences beforehand. Its limits: a band is just a fragment of a certain size, unrelated fragments can coincide, and scoring bands as present or absent usually can't tell every genotype apart. The method (making profiles) is different from an AFLP marker (one scored, variable band).

 

Amplified fragment length polymorphism is a multilocus molecular fingerprinting technique. Genomic DNA is digested with restriction enzymes, producing a large fragment population, and adaptors are ligated to fragment ends to supply known priming sites. PCR primers complementary to the adaptor and restriction site carry additional selective bases that preferentially match flanking sequence, so only a subset of fragments is efficiently amplified; the products are size-separated into a profile. Variable features among samples are scored as AFLP markers, and the original Vos et al. method emphasizes that this requires no prior sequence knowledge of the loci sampled. The underlying abstraction is controlled subsampling of a complex fragment population followed by comparative pattern readout, which only works when profiles are generated under the same selection and detection conventions. A band is a size-defined signal, not a uniquely identified locus: co-migrating unrelated fragments (size homoplasy) can occur, and presence/absence scoring typically makes AFLP behave as a dominant marker that cannot resolve all genotypes. The method (profile generation) and the marker (a scored variable feature) should be kept distinct, and neither a band nor a banding difference proves the causal DNA change or true homology.

Scope of Application

The method supports genetic-diversity and fingerprinting studies when comparable samples and scoring conventions are available. Park and colleagues used AFLP profiles to distinguish 74 tomato cultivars in a reported study. That result is study-specific, not a guarantee of unique fingerprints for every collection.[2]

Clarity

An observed band is a size-defined assay signal, not necessarily a uniquely identified sequence. Equal-size but unrelated fragments can comigrate, and standard presence/absence markers may not resolve every genotype. A difference in bands supports qualified polymorphism inference but does not by itself identify the underlying variant.[3]

Manages Complexity

Selective access reduces a huge genomic fragment population to a manageable multilocus profile. The advantage of broad anonymous coverage comes with loss of locus identity and possible similarity errors from comigration.[1][3]

Abstract Reasoning

Identify the restriction-derived fragment population, its reproducible selective amplification, the comparable size profile and the inferential limits of matching or missing bands. Plain amplification or electrophoresis alone lacks the full AFLP architecture.

Knowledge Transfer

The method can transfer among genomic fingerprinting settings with suitable comparable profiles. A generic “fingerprint” of non-genomic data is an analogy to selective patterning, not an AFLP instance.

Neighborhood in Abstraction Space

Amplified Fragment Length Polymorphism sits in a moderately populated region (56th percentile for distinctiveness): it has near-neighbors but no dense thicket of look-alikes.

Family — Molecular Biology & Genetic Engineering Methods (21 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-31

References

[1] Pieter Vos et al. (1995). AFLP, a new technique for DNA fingerprinting. Nucleic Acids Research 23, 4407–4414. https://doi.org/10.1093/nar/23.21.4407. Full paper directly inspected, including Figure 4 and discussion. registry ↩a ↩b

[2] Young Hoon Park, Marilyn A. L. West, and Dina A. St Clair (2004). Evaluation of AFLPs for germplasm fingerprinting and assessment of genetic diversity in cultivars of tomato (Lycopersicon esculentum L.). Genome 47, 510–518. https://doi.org/10.1139/g04-004. Original study abstract directly inspected. registry ↩

[3] Gerrit Gort, Theo van Hintum, and Fred van Eeuwijk (2009). Homoplasy corrected estimation of genetic similarity from AFLP bands, and the effect of the number of bands on the precision of estimation. Theoretical and Applied Genetics 119, 397–416. https://doi.org/10.1007/s00122-009-1047-9. Abstract and introduction directly inspected. registry ↩a ↩b