Oligonucleotide probe sequences, their targets and the hybridization conditions used in this study.

New probes developed in the present study have been designed with the ARB software package [46] and tested against a panel of reference strains for specificity (ACT218, Aa829, LAB759, Sel1469 and Fnav1254) or tested on subgingival plaque samples at increasing formamide concentrations to define assay conditions for maximum stringency and optimal specificity (TrepG1, Pendo740 and SynA1409). Probe LAB759 showed cross-reactivity with Eikenella corrodens and not identified cocci. In the present study, only rods gave a positive signal with probe LAB759.