Microbial Insights

In some cases such as a chlorinated or petroleum solvent contaminated site, or a sulfate-reducing location, one might expect to find particular genus or species (e.g. Dehalococcoides, Sulfobacter). DGGE can show that a certain genus is present if it is a major member of the community (~2% of the microbial population). It is important to keep in mind that although the desired bacteria may be part of the microbial population, it may not be seen as a band in the DGGE profile simply because it is not present in sufficient numbers. Because of this limitation with the DGGE Bac analysis which amplifies 16S rRNA from all organisms within a sample, we also have developed specialized DGGE using particular primers to isolate DNA from desired groups (fungal, SRB). These primers act as hooks to attach to DNA from organisms within the desired bacterial group, DNA obtained using these primers is then subjected to DGGE but because other background DNA has been removed, there is more likelihood of seeing organisms within the desired group.  When there is a need to verify the presence of particular genera or bacterial group, CENSUS (qPCR) provides the most accurate and reliable detection and quantification.