Parallel DGGE Overview:
Parallel DGGE is based on the application of a denaturant concentration gradient - increasing in the direction of electrophoresis within a polyacrylamide gel - and uniform temperature to induce the partial unwinding or melting of double-stranded DNA by distinct domains in a sequence-specific manner. Melting breaks the hydrogen bonds holding together each base pair within a DNA sequence: with domains rich in GC base pairs melting at higher temperatures than those with high A-T base-pair content.

Incorporating sequence high in G-C content into the DNA target sequence by PCR® amplification (GC-clamping) prevents the DNA target with the lowest melting domain from melting completely at its predetermined Tm, which is maintained by the application of a constant temperature across the gel and within the buffer. Because both gel temperature and increasing denaturant concentration act to melt DNA in a sequenceand domain-specific manner, any point mutations amplified within a PCR® product will affect its Tm so that its subsequent mobility within a polyacrylamide gel differs from its wild type counterpart (see schematic diagram).

Consequently, the sensitivity of this technique in distinguishing individual DNA sequences, which might differ only by a single point mutation, has proven highly attractive to scientists screening for unknown mutations.

Complete System Includes:

• Twin-plate maxi-gel unit with GRM, heated gel tank with PT100 temperature sensor and thermometer, lid,
• 2 x (20.5 x 20cm; W x H) plain glass plates
• 2 x (20.5 x 20cm) notched glass plates, 4 x 1mm spacers,
• 2 x spacer aligners and 2 x 1mm thick 24-sample combs,
• casting base, 2 x silicone seals and 1 x dummy plate;
• plus GM100 gradient mixer and heat sensor control unit