{
  "patent_number": "US 4683194",
  "country": "US",
  "title": "Detecting Genetic Differences Using DNA Probes and Enzymes",
  "original_title": "Method for detection of polymorphic restriction sites and nucleic acid sequences",
  "summary": "This 1987 patent describes a method to find tiny differences in DNA sequences by using special DNA pieces (probes) and cutting enzymes, which can help diagnose genetic conditions like sickle cell anemia.",
  "what_it_does": "This patent outlines a way to spot specific changes in DNA. You start with a DNA sample and a short, custom-made DNA piece called a probe. This probe is designed to match a specific part of the DNA you're interested in, and it's tagged with a label (like a radioactive marker or a fluorescent dye) near where a potential difference might be. The probe is mixed with the DNA sample, and if the DNA sequence matches, the probe sticks to it. Then, a special enzyme that acts like molecular scissors is used. If the DNA has the specific spot the enzyme cuts, it snips the probe. By separating the cut and uncut probes and looking at their labels, scientists can tell if the specific DNA sequence, and thus the restriction site, is present or absent. Claim 1 details this process, including hybridizing, digesting with a restriction endonuclease, separating fragments, and detecting. Claim 2 adds a step using a 'blocking oligomer' to make the test more precise by preventing the probe from sticking to similar but incorrect DNA sequences.",
  "what_it_does_not_cover": [
    "Methods that do not use an oligonucleotide probe complementary to the target nucleic acid sequence.",
    "Methods that do not involve digesting the hybridized nucleic acid with a restriction enzyme.",
    "Methods where the probe is not labeled at the end nearer the restriction site.",
    "Techniques that do not separate labeled cleaved fragments from labeled uncleaved fragments.",
    "Methods that do not detect the presence or absence of labeled fragments.",
    "Detecting nucleic acid sequences without looking for specific restriction sites."
  ],
  "filed": "1985-03-28",
  "granted": "1987-07-28",
  "expires": null,
  "status": "active",
  "holder": "Cetus Corp",
  "holder_url": "https://patentbrief.org/company/cetus-corp",
  "inventors": [
    {
      "name": "Randall K. Saiki",
      "url": "https://patentbrief.org/inventor/randall-k-saiki"
    },
    {
      "name": "Henry A. Erlich",
      "url": "https://patentbrief.org/inventor/henry-a-erlich"
    }
  ],
  "times_cited": 289,
  "tags": [
    "biotech",
    "pharmaceutical",
    "medical_devices",
    "research_tools"
  ],
  "abstract": "In a method for detecting the presence or absence of a specific restriction site in a nucleic acid sequence an oligonucleotide probe complementary to one strand of the nucleic acid sequence spanning said restriction site is synthesized. The probe is labeled at the end nearer the restriction site. The nucleic acid is hybridized to the probe and a blocking oligomer may be added, if necessary, to prevent non-specific binding of the probe. Subsequent digestion with a restriction enzyme cleaves those oligomers that have hybridized to the nucleic acid and reformed the restriction site. The resulting cut and uncut labeled oligomers are separated and detected based on the type of probe label. The described method may be used to detect sickle cell anemia.",
  "url": "https://patentbrief.org/patent/us/4683194/pcr-process",
  "markdown_url": "https://patentbrief.org/patent/us/4683194/pcr-process/md",
  "google_patents_url": "https://patents.google.com/patent/US4683194",
  "relatedPatents": []
}