Specific DNA probes in diagnostic microbiology
First Claim
1. A method for detecting the presence of a pathogen in a clinical sample suspected of containing said pathogen, said method comprising:
- depositing said sample on an inert support;
treating said sample to affix genetic material of any of said pathogen present in said sample to said support in substantially single stranded form at substantially the same site on said support where said sample was deposited;
contacting said fixed single stranded genetic material with a labeled probe having a nucleotide sequence of at least about 25 bases at least substantially complementary to a nucleotide sequence of a structural gene characteristic of said pathogen, said contacting being under hybridizing conditions at a predetermined stringency; and
detecting duplex formation on said support by means of said label.
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Accused Products
Abstract
Method and compositions for infectious disease diagnosis and epidemiology involving labeled nucleotide probes complementary to nucleic acid coding for a characteristic pathogen product. Clinical isolates are cultivated, expanding the number of microorganisms, the resulting colonies lysed, the genome normally denatured and then fixed. Alternatively, clinical samples (stool, sputum, pus, etc.) are spotted onto an inert support. The sample is treated in such a way that the DNA is liberated from microbes present in the sample and complexed onto the support. The DNA is normally denatured and fixed in this process. Subsequently, a labelled polynucleotide probe specific for a DNA sequence characteristic of a pathogenic product suspected of being present in the clinical sample is contacted with the fixed genomic single stranded nucleic acid under hybridizing conditions. Hybridization of probes to the single stranded nucleic acid is diagnostic of the presence of the pathogen.
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Citations
20 Claims
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1. A method for detecting the presence of a pathogen in a clinical sample suspected of containing said pathogen, said method comprising:
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depositing said sample on an inert support; treating said sample to affix genetic material of any of said pathogen present in said sample to said support in substantially single stranded form at substantially the same site on said support where said sample was deposited; contacting said fixed single stranded genetic material with a labeled probe having a nucleotide sequence of at least about 25 bases at least substantially complementary to a nucleotide sequence of a structural gene characteristic of said pathogen, said contacting being under hybridizing conditions at a predetermined stringency; and detecting duplex formation on said support by means of said label. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for detecting the presence of a unicellular pathogen in a sample suspected of containing said pathogen, said method comprising:
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depositing said sample on an inert porous filter as a plurality of individual portions; transferring said filter to a bibulous material wetted with a reagent solution capable of lysing said pathogen and denaturing the genetic material of said pathogen to provide single stranded DNA; heating said filter to fix said single stranded DNA at substantially the same site as the individual portion from which said genetic material is derived; contacting said fixed single stranded DNA with a labeled probe having a nucleotide sequence of at least about 25 bases at least substantially complementary to a nucleotide sequence of a structural gene characteristic of said pathogen under hybridizing conditions of a predetermined stringency,; and detecting duplex formation on said support by means of said label. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method for detecting the presence of a gram negative bacillus in a clinical isolate suspected of containing said bacillus, said method comprising:
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spotting said clinical isolate onto an inert porous filter; contacting said spotted inert porous filter with a nutrient gel, whereby nutrients diffuse to said bacillus in said spot, whereby a colony forms; transferring said filter supporting said colony onto a bibulous material containing a reagent solution for lysing said bacillus and denaturing the genome of said bacillus to provide single stranded DNA at substantially the same site as said colony; heating said filter to fix said single stranded DNA to said filter; contacting said filter with said fixed single stranded DNA, with a radioactively labeled probe having a nucleotide sequence of at least about 25 bases and at least substantially complementary to a nucleotide sequence of a structural gene characteristic of said bacillus under hybridizing conditions of a predetermined stringency; and detecting duplex formation on said support by means of said radioactive isotope. - View Dependent Claims (18, 19, 20)
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Specification