FIG. 2.

Identification of “Candidatus Thioturbo danicus” by whole-cell fluorescent in situ hybridization. (A) Phase-contrast image of all cells. (B) Cells hybridized with a mixture of three probes, i.e., probe FB648 labeled with fluorescein (green) and specific for “Candidatus Thioturbo danicus,” probe ARC1430 labeled with Cy3 (red) and specific for members of the genus Arcobacter, and probe EUB338mix, which is labeled with Cy5 (blue) and specific for all Bacteria. Note the presence of three different bacterial populations, i.e., cells of “Candidatus Thioturbo danicus” stained light blue (green plus blue), cells affiliated with Arcobacter stained pink (red plus blue), and spirillum-shaped cells stained blue. Bar, 10 μm.