Labelled trinucleotides as quantitative probes to identify Bacillus spp. using fluorescent in situ hybridization

The number of nucleotide triplet repeats in 16 S rRNA sequences can be used for detection and identification of bacteria. Labelled TTT, GGG and ATA triplets were hybridized to the ribonucleic acid of Bacillus subtilis and Bacillus fusiformis whole-cells and the number of such triplets was quantified by synchronous fluorescence spectrometry. Each species was distinctly identified by specific ratios of labelled TTT, GGG and ATA triplets as well as characteristic fluorescence spectra. Notwithstanding the absence of intrinsic specificity, fluorescein-conjugated nucleotide triplet probes appear to be a useful tool for fluorescent spectrometric identification of micro-organisms through the quantitation of trinucleotide repeats.