October Term 2011 · Docket 10-1150

Can a patent cover a natural law plus standard medical steps?

Prometheus claims a patent on a drug-dosing method. Mayo argues the claim covers a natural law and blocks public use.

Official caption
Mayo Collaborative Services v. Prometheus Laboratories, Inc.
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Verified source milestones

  1. — An official oral-argument transcript was verified.
  2. — An official oral-argument transcript was verified.

The arguments, in order

This case may have been argued more than once. Each entry below uses that session's official transcript. Later arguments do not erase earlier ones.

  1. Argument 1 ·

    What happened at the argument

    Mayo's lawyer argued the patent claims a natural law.

    Prometheus's lawyer argued the patent covers a specific process.

    Justices questioned the scope of the patent claim.

    Read the official transcript for this argument · Official argument details

    Sources used for this argument breakdown

A citizen's guide to the whole case

What this case is about

Prometheus Laboratories holds a patent on a method for dosing a drug. The method involves measuring blood levels and adjusting the dose based on those levels. Mayo Collaborative Services uses a similar method. Prometheus sued for patent infringement. The lower courts found the patent invalid. They ruled the claim covers a natural law.

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How the case got here

The Supreme Court heard oral argument in this case on December 7, 2011.

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What each side wants

Prometheus wants the Court to restore its patent on the dosing method.

Mayo wants the Court to keep the patent invalid and allow public use.

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What each side says

Prometheus argues the patent covers a specific, useful process.

Mayo argues the patent claims a natural law and blocks public research.

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What the justices asked

Justice Sotomayor asked if the patent covers a specific machine or just a range.

Justice Kennedy asked how this case compares to previous patent cases involving machines.

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Why it matters

This case defines what medical methods can be patented. It affects how doctors and researchers use drug-dosing information. It shapes the balance between private patents and public knowledge.

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What happens next

This article currently covers the argument record. Use the official docket link for later case activity.

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Official Court provenance

Official docket and case history · Official Supreme Court oral-argument detail page

Title and summary sources

Revision history

  1. Revision 1 · Official Transcript ·

    Correction: Rewritten to the concise citizen-facing editorial standard.

  2. Revision 2 · Official Transcript ·

    Correction: Migrated to the dated official Court activity contract without model use.

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