How many genome editing techniques have been discovered?

Broadly speaking, there are three major genome editing techniques in use today. Although each works slightly different, all of them rely on biologic scissors, called “nucleases” that cleave DNA. These include zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and the more recently discovered Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) nucleases.

They all can be used to delete, insert, or alter any type of DNA, including that of humans, animals, plants, or microorganisms like bacteria.

The CRISPR genome editing system is the most recently described and relies on a combination of a specifically designed biological guide that can find and bind to a specific DNA sequence, and a nuclease which edits or removes the targeted DNA that is the root cause of a disease. Different guides can be created to target different DNA sequences enabling multiple sites within a genome to be targeted in a single procedure. This makes for the versatility of the technique which has the potential to cure complex diseases at the genetic level.