FIG. 4.

FISH of fixed cells detached mechanically from straw incubated in soil slurries without (a) and with (b) prior treatment by toluidine blue. Two 16S rDNA probes were used simultaneously: CY5-labeled bacterial-domain probe Eub338 (blue) and FITC-labeled probe Clost I (green). One sample (b) was additionally treated with toluidine blue to reduce autofluorescence, especially in the green channel. Scale bars, 5 μm.