Denaturing gradient gel electrophoresis (DGGE).

Denaturing Gradient Gel Electrophoresis (DGGE) is a technique used to separate short- to medium-length DNA fragments based on their melting characteristics. It has been used frequently for identifying single-nucleotide polymorphisms without the need for DNA sequencing and as a molecular fingerprinting method for complex ecosystem communities, in particular in conjunction with amplification of microbial 16S rRNA genes. Here, the principles of DGGE, based on partial DNA strand separation at a given position in a gradient of chemical denaturant, are described, and an example protocol, optimized for fingerprinting of 200-300 bp fragments of bacterial 16S rRNA genes, is given.