Denaturing gradient gel electrophoresis gel expansion (DGGEGE)--an attempt to resolve the limitations of co-migration in the DGGE of complex polymicrobial communities.

Recent molecular approaches for the study of microbial communities such as PCR-cloning have enabled the detection and identification of as-yet-unculturable taxa. Cloning and sequencing of multiple samples is extremely laborious and expensive to perform thoroughly due to the large diversity involved. For this purpose, techniques such as denaturing gradient gel electrophoresis (DGGE) may be better suited.

Statistical analyses of complex denaturing gradient gel electrophoresis profiles.

Studies using molecular techniques have demonstrated that a culture-based approach can severely underestimate the bacterial diversity in most environments. One of the molecular techniques that has been applied in microbial ecology is denaturing gradient gel electrophoresis (DGGE). The purpose of this study was to investigate differences in the microbiota of plaque, using a number of analysis techniques, from children without gingivitis (n = 30) and from those with gingivitis (n = 30).

Prevalence of periodontal pathogens in dental plaque of children.

Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Tannerella forsythensis have been implicated as the main etiological agents of periodontal disease. The purpose of this work was to estimate the prevalence of these organisms in plaque from children without gingivitis (group 1; n = 65) and from those with gingivitis (group 2; n = 53). Extracted DNA from plaque was subjected to two rounds of PCR targeting the 16S rRNA gene using both universal primers and species-specific primers.