Bacteria and Archaea Fluorescence in Situ Hybridization (FISH) Analyses

Fluorescence in situ Hybridization, also known as "FISH," is a technique used to detect the presence of specific groups of Bacteria and Archaea microbes.

Inside active cells, molecules called rRNA are involved in the synthesis of proteins which are manufactured according to a specific code which is carried in the strand of DNA in the cell. In the lab, it is possible to artificially manufacture a probe which is a small strand of DNA which will match exactly with the sequence on a specific rRNA target molecule. This probe can be labelled with a fluorescent dye and will bind (hybridise), on the basis of complementary base pairing to the matching DNA in the cells (in situ). The fluorescent dye allows the cell to be observed under a microscope. The technique allows for the direct quantification of specific types of Bacteria and Archaea in microbial populations without the need to culture the cells in growth media. Only living cells contain sufficient rRNA to allow detection by FISH.

By selecting carefully from a range of ready-to-use domain-, divisiongenus- and species-specific probes, FISH analysis provides an analytical technique for detailed study of microbial populations in both natural and engineered environments.

Advantages of the FISH Microbial Detection Method:

  • Rapid results – results for FISH available in 2 to 3 days, compared with up to 28 days for viable culture dependent SRB MPN counts
  • FISH counts are 99% accurate, giving a 2-3 log higher count than traditional viable counts
  • FISH can detect specific groups of SRB within the general SRB population
  • The sample can be preserved on site
  • FISH requires no prior knowledge of the environmental conditions of the system


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