Methods and materials for detecting contaminated food products

Abstract

This document provides methods and materials for detecting contaminated food products. For example, methods and materials for using an enzymatic amplification cascade of restriction endonucleases to detect nucleic acid of a microorganism or virus (e.g., a pathogen) within a sample (e.g., food product sample) being tested, thereby assessing a food product for possible contamination are provided.

What is claimed is: 
     
         1 . A method for assessing a food product for contamination, said method comprising:
 (a) contacting a sample from said food product with a probe nucleic acid comprising an amplifying restriction endonuclease and a nucleotide sequence complementary to a sequence of a target nucleic acid present within a microorganism or virus under conditions wherein, if said target nucleic acid is present in said sample, at least a portion of said target nucleic acid hybridizes to at least a portion of said probe nucleic acid to form a double-stranded portion of nucleic acid comprising a restriction endonuclease cut site,   (b) contacting said double-stranded portion of nucleic acid with a recognition restriction endonuclease having the ability to cut said double-stranded portion of nucleic acid at said restriction endonuclease cut site under conditions wherein said recognition restriction endonuclease cleaves said double-stranded portion of nucleic acid at said restriction endonuclease cut site, thereby separating a portion of said probe nucleic acid comprising said amplifying restriction endonuclease from at least another portion of said probe nucleic acid,   (c) contacting said portion of said probe nucleic acid comprising said amplifying restriction endonuclease with a reporter nucleic acid comprising a double-stranded portion of nucleic acid comprising a restriction endonuclease cut site of said amplifying restriction endonuclease under conditions wherein said amplifying restriction endonuclease cleaves said reporter nucleic acid at said restriction endonuclease cut site of said amplifying restriction endonuclease, thereby separating a portion of said reporter nucleic acid from at least another portion of said reporter nucleic acid, and   (d) determining the presence or absence of said portion of said reporter nucleic acid, wherein the presence of said portion of said reporter nucleic acid indicates that said sample contains said target nucleic acid and is thereby contaminated, and wherein the absence of said portion of said reporter nucleic acid indicates that said sample does not contain said target nucleic acid and is thereby not contaminated.