A NEW SENSITIVE, WHOLE-CELL HYBRIDIZATION TECHNIQUE FOR DETECTION OF BACTERIA INVOLVING A BIOTINYLATED OLIGONUCLEOTIDE PROBE TARGETING RIBOSOMAL-RNA AND TYRAMIDE SIGNAL AMPLIFICATION

A tyramide signal amplification system with biotinylated oligonucleoti de probes and streptavidin-horseradish peroxidase was used to increase the sensitivity of fluorescent in situ hybridization techniques. When applied to both gram-negative and -positive bacteria immobilized on g lass slides, a 7- to 12-fold amplification of the fluorescence signal was observed relative to that of cells hybridized with fluorescently m onolabeled probes. A large proportion (62 to 78%) of bacteria could be detected under starvation conditions and in natural samples from the marine environment. This amplification procedure allows new investigat ions in marine oligotrophic ecosystems and water quality control.