Denaturing gradient gel electrophoresis (DGGE) is a variant of gel electrophoresis that detects single nucleotide changes or small insertions or deletions in DNA. The main advantage of DGGE is its sensitivity. DGGE can detect virtually all mutations in a given piece of DNA. Because of this, it is often used in genetic screening.

The duplex DNA, usually between 100 and 300 nucleotides long and generated by the polymerase chain reaction (PCR), is forced through a gel which contains an increasing concentration of a denaturant (i.e., a chemical such as formamide) used to break apart (melt or denature) the DNA. When the DNA reaches a certain concentration of formamide in the gel, the duplex denatures. This denatured DNA is essentially stopped (arrested) at that point in the gel, and forms a sharp band. The position of the band can be affected by a single...