Solution hybridization assay for detecting genetically engineered microorganisms in environmental samples.

A solution hybridization method was developed for detecting genetically engineered microorganisms in environmental samples. The detection method involves recovery of DNA from the microbial community of an environmental sample followed by hybridization in solution with a radiolabeled RNA gene probe. After nuclease digestion of non-hybridized probe RNA, the DNA-RNA hybrids formed in the solution hybridization reaction are separated by sephadex or hydroxyapatite column chromatography and detected by liquid scintillation counting. Using solution hybridization-gene probe detection, as few as 100-1000 target cells per gram sediment sample of a 2,4,5-T-degrading genetically engineered microorganisms could be detected.