Fig. 5

Detection of the gut haloarchaea by fluorescence in situ hybridisation (FISH). a The binding specificity of the haloarchaea-specific probe HALO775_Cy3 (red) to a cultured bacterium (Escherichia coli K12), haloarchaeon (Haloplanus salinus JCM 18368^T) and other archaeon (Methanobrevibacter smithii JCM 30028^T) were tested. A probe EUB338_Cy5 (green) was used for detection of bacteria. A counterstain was performed using DNA staining solution (4′,6-diamidino-2-phenylindole, DAPI; blue). b To verify the presence of haloarchaea in the human gut, three faecal samples (J0885, J0111 and J0054) were subjected to FISH analysis. Non-binding probe (NONEUB_FAM) was included to decipher false positives. Scale bars correspond to 5 μm