This educational guide is based on the linked primary sources. It is not a Court publication, is not affiliated with the Court, and is not legal advice.
In brief
Overview
During oral argument, the Justices asked several questions about the patentability of a law of nature and the novelty of the claims.
Background and question before the Court
Justice Breyer asked: “What has to be added to a law of nature to make it a patentable process?”
What each side argues
Petitioner (Mayo Collaborative Services)
According to Mr. Bress, the petitioner argued that under 35 U.S.C. § 103, a claim would be obvious to a person of ordinary skill in the art.
Respondent (Prometheus Laboratories)
Source-limited. The record does not yet support a complete account.
What happened at oral argument
Justice Kennedy asked: “Why couldn’t someone come…?”
Justice Scalia asked: “Suppose somebody thinks you’re wrong… they want to develop better numbers that will help the medical profession.”
Justice Sotomayor asked: “So, it’s novel? What’s your answer about why this is novel?”
What the Court decided
Why it matters
Terms to know
No glossary terms are available for this guide.
Primary sources
Read the source materials on the official site or open the immutable repository copy used for this guide.
- 0b17b0fef16eace7e17c-r1-a2ba4819444404cb.pdforal argument transcript
Guide generated September 24, 2026. Automated validation accepted this version.