During recent years,molecular techniques such as PCR and denaturing gradient gel electrophoresis (DGGE) or DNA sequencing have revolutionized all fields of microbiology,and sensitive detection and exact identification of bacteria are possible.Fluorescence in situ hybridization (FISH) using 16SrRNA probes does not rely on PCR amplification,and as such provides a useful complementary technique to DGGE for the analysis of organisms. Because of FISH allowing nucleic acid sequences to be examined inside cells w...