Gene editing techniques compared

Published

Five methods, three decades, one goal. Each finds a chosen stretch of DNA and changes it, but they get there in different ways.

What are the main gene-editing techniques?

The five best-known methods are zinc finger nucleases (1996), TALENs (2010), CRISPR/Cas9 (2012), base editing (2016) and prime editing (2019). The first three cut both DNA strands; the last two change the sequence without doing so.

At a glance

The table sets the five side by side, each as first described in its founding paper.

Five gene-editing methods, as first described
MethodHow it finds its targetWhat it does to the DNAFirst described
CRISPR/Cas9A guide RNA pairs with the target sequence [1]Cuts both DNA strands at the chosen site [1]2012 [1]
TALENsA custom TAL effector protein that binds the target sequence [2]A FokI cutting domain breaks both strands at the site [2]2010 [2]
Zinc finger nucleasesZinc finger proteins built to match the target [3]A FokI cutting domain cuts near the site [3]1996 [3]
Base editingA guide RNA, as with CRISPR [4]Converts one DNA base into another without cutting both strands [4]2016 [4]
Prime editingA prime editing guide RNA that also carries the edit [5]Writes a short new sequence into the site without cutting both strands [5]2019 [5]

The cutters

Zinc finger nucleases, TALENs and CRISPR/Cas9 are site-directed nucleases: they break both DNA strands at a chosen place and leave the cell to repair it [1][2][3]. Guidance in England describes three kinds of result. In SDN1, the cell simply rejoins the break. SDN2 uses a template for a small change, and SDN3 inserts a longer stretch of DNA [6].

The letter-changers

Base editing converts one DNA base into another without cutting both strands or needing a donor template [4]. Prime editing writes a short new sequence into the site, again without a double-strand break or donor DNA [5]. Guidance in England notes that both make the same type of genetic change that occurs naturally [6].

What they share

Every nuclease can occasionally cut at sites that resemble its target, so target choice matters for all of them [8]. The European Food Safety Authority's 2012 opinion concluded that off-target changes from inserting DNA with site-directed nucleases would be fewer than those from most mutagenesis techniques [7].

Guides in this section

  • CRISPR/Cas9: A guide RNA steers the Cas9 enzyme to cut both strands.
  • TALENs: A custom TAL effector protein finds the site; FokI cuts it.
  • Zinc finger nucleases: Designed zinc finger proteins find the site; FokI cuts it.
  • Base editing: Converts one DNA letter into another without a double-strand break.
  • Prime editing: Writes a short new sequence in from a template on its guide RNA.

Frequently asked questions

Which gene-editing method is the oldest?

Zinc finger nucleases, first reported in 1996, followed by TALENs in 2010 and CRISPR/Cas9 in 2012.

Which methods do not cut both DNA strands?

Base editing and prime editing. Both nick a single strand and change the sequence directly.

Are all five used in plants?

Yes. Each has been used in crops, including rice, wheat, maize, cotton and tomato.

References

  1. Science (2012). A programmable dual-RNA-guided DNA endonuclease in adaptive bacterial immunity (Jinek and others)
  2. Genetics, via PubMed (2010). Targeting DNA double-strand breaks with TAL effector nucleases (Christian and others)
  3. Proceedings of the National Academy of Sciences (1996). Hybrid restriction enzymes: zinc finger fusions to Fok I cleavage domain (Kim, Cha and Chandrasegaran)
  4. Nature (2016). Programmable editing of a target base in genomic DNA without double-stranded DNA cleavage (Komor and others)
  5. Nature (2019). Search-and-replace genome editing without double-strand breaks or donor DNA (Anzalone and others)
  6. Advisory Committee on Releases to the Environment, GOV.UK (2025). ACRE guidance on producing precision bred plants
  7. EFSA Panel on Genetically Modified Organisms, EFSA Journal (2012). Scientific opinion addressing the safety assessment of plants developed using Zinc Finger Nuclease 3 and other Site-Directed Nucleases with similar function
  8. Plant Cell Reports (2019). CRISPR/Cas precision and off-targeting in plants (Hahn and Nekrasov, title shortened)

Last reviewed 2026-09-26. Edited by Mark Turner.