The ligase chain reaction (lcr) enables as few as 10 dna targets to be amplified to levels detectable using many conventional detection methods. The amplification technology can be applied to the detection of salmonella in food samples with benefits realized in the reduction of pre-enrichment and selective enrichment growth times and improvement in assay sensitivity, surpassing all current detection assays. Phase I objectives are to construct a salmonella genomic DNA library and begin identification of one or more salmonella sequences of 30-80 bases in length to be used as probe sets for amplification of target salmonella cells in food samples. In Phase II, DNA corresponding to the sequences identified will be synthesized and screened for ability to detect all important salmonella species and not cross-react with common food-borne and enteric organisms. The probe sets that fulfill these criteria will be put into the lcr assay. In addition, issues of sample preparation, definition of lCR conditions for optimal reactivity and food testing will be undertaken.
