Table 1.

Oligonucleotide probes used in this study.

Probe	Target group	Sequence (5′-3′)	Target sitea	% Formamide in ISHb buffer	Reference
EUB338	Bacteria	GCTGCCTCCCGTAGGAGT	16S (338–355)c	0–50	Amann et al., 1990
NON338	Negative control	ACTCCTACGGGAGGCAGC	16S (338–355)c		Amann et al., 1990
ALF968	Alphaproteobacteria	GGTAAGGTTCTGCGCGTT	16S (968–986)e	20	Glöckner et al., 1999
CF319a	Bacteroidetes	TGGTCCGTGTCTCAGTAC	16S (319–336)d	35	Manz et al., 1996
GAM42a	Gammaproteobacteria	GCCTTCCCACATCGTTT	23S (1027–1043)c	35	Glöckner et al., 1999

^aE. coli numbering; ^bIn situ hybridization; ^cCy3; ^dATTO425; ^eAlexa594.