From our private database of 14,200+ case briefs...
Mayo Collaborative Services v. Prometheus Laboratories, Inc.
United States Supreme Court
132 S.Ct. 1289 (2012)
Thiopurine is a drug that has been used to treat various illnesses, such as acute leukemia and autoimmune disorders. When a person ingests a thiopurine compound, the body metabolizes it in a manner that frequently differs from most other individuals. As a result, it was difficult to discern whether a particular dosage given to an individual was too high, risking harmful side effects, or too low and thus ineffective. Prometheus Laboratories, Inc. (Prometheus) (plaintiff) filed two patent applications that described the findings of tests used to determine whether a particular thiopurine dosage was too high or too low. Thereafter, Prometheus created diagnostic tests for sale that embodied the processes the patents described. Mayo Collaborative Services and Mayo Clinic Rochester (collectively Mayo) (defendant) purchased the diagnostic tests created by Prometheus. Several years later, Mayo announced that it intended to sell its own test, using a different thiopurine level to determine toxicity. Prometheus filed suit against Mayo in federal district court claiming patent infringement. The district court granted Mayo’s motion for summary judgment. In doing so, the court noted that Prometheus’ patents claimed natural phenomena that could not be patented. The court of appeals for the federal circuit reversed and upheld the patent applications. The U.S. Supreme Court granted certiorari to review.
Rule of Law
Holding and Reasoning (Breyer, J.)
What to do next…
Unlock this case brief with a free (no-commitment) trial membership of Quimbee.
You’ll be in good company: Quimbee is one of the most widely used and trusted sites for law students, serving more than 97,000 law students since 2011. Some law schools—such as Yale, Vanderbilt, Berkeley, and the University of Illinois—even subscribe directly to Quimbee for all their law students. Read our student testimonials.
Learn more about Quimbee’s unique (and proven) approach to achieving great grades at law school.
Quimbee is a company hell-bent on one thing: helping you get an “A” in every course you take in law school, so you can graduate at the top of your class and get a high-paying law job. We’re not just a study aid for law students; we’re the study aid for law students. Read more about Quimbee.
Here's why 239,000 law students have relied on our case briefs:
- Written by law professors and practitioners, not other law students. 14,200 briefs, keyed to 189 casebooks. Top-notch customer support.
- The right amount of information, includes the facts, issues, rule of law, holding and reasoning, and any concurrences and dissents.
- Access in your classes, works on your mobile and tablet. Massive library of related video lessons and high quality multiple-choice questions.
- Easy to use, uniform format for every case brief. Written in plain English, not in legalese. Our briefs summarize and simplify; they don’t just repeat the court’s language.