Characterization of Microorganisms by FISH

The methane emission from a habitat is determined by the methane producing and methane oxidising microorganisms. For the characterisation of these communities we use the fluorescence in situ hybridisation method (FISH). FISH with rRNA-targeted oligonucleotide probes allows to visualise, identify and localise bacterial cells of selected phylogenetic groups directly in environmental samples. For this purpose, a fluorescence dye is bound to an oligonucleotide, this complex is called rRNA-probe. These probes form stable hybrids only with the complementary sequence, so the probe binding is highly specific (see figure).

The figures above show an example for FISH with a sample of organic rich soil from our study site in the Lena river delta.