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
According to Jonathan S. Franklin (Petitioner), according to Jonathan S. Franklin (Petitioner), according to Jonathan S. Franklin (Petitioner), the case concerns a patent claim covering homocysteine testing that the petitioner says is infringed whenever a doctor looks at a homocysteine test result and thinks about a natural correlation.
According to Jonathan S. Franklin (Petitioner), the petitioner asserts that the patent has led to multimillion‑dollar damages and an injunction prohibiting any testing company from conducting homocysteine tests by any method for any reason.
The United States Department of Justice, as amicus, argues that claim 13 satisfies the written‑description, enablement, and definiteness requirements of §112 of the Patent Act.
Background and question before the Court
Justice Kennedy asked whether the second point was definiteness.
Justice Stevens asked about the patent’s validity under §101.
Justice Souter asked for a greater‑detail explanation.
Justice Scalia asked what was made by man here.
Justice Stevens asked whether the case would be different if they quoted §101 in their appendix.
What each side argues
Petitioner Position
According to Jonathan S. Franklin (Petitioner), according to Jonathan S. Franklin (Petitioner), according to Jonathan S. Franklin (Petitioner), the patent claim is infringed whenever any doctor looks at a homocysteine test result and reflexively thinks about a basic natural correlation.
According to Petitioner, commercial laboratory companies like LabCorp are selling the test to practice our invention.
According to Petitioner, anyone who makes, uses or sells the invention is potentially liable as an infringer.
According to Mr. Franklin, it applies to any homocysteine test, no matter how it’s done, no matter what reason it’s done, no matter if it’s in the prior art, no matter if I invent it tomorrow.
According to Mr. Franklin, so I don’t think the Court needs to get into the inquiry, and I don’t think the Patent Office really wants to get into that inquiry either.
Respondent Position
According to Mr. Estrada, LabCorp never asked the trial judge or the Federal Circuit to declare this patent invalid under §101, which is an affirmative defense they had to plead in the answer and prove by clear and convincing evidence.
According to Mr. Estrada, in the Morse case, claim 8, it had been known for many years that it was possible to transmit using the electromagnetic current but nobody knew how. This Court’s ruling on page 107 says this was known by men of science everywhere.
According to Unidentified Party Representative, we are only asking that the Court give further guidance on this patent and to say that a patent that claims nothing more than a natural correlation preceded by the inherent and generic step of measuring the input for that correlation is invalid and the judgment that is based upon it should also be reversed.
What happened at oral argument
Oral argument before the Supreme Court began at 11:12 a.m.
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.
- 1a423beb0cd3a9b438a3-r1-8e14f67b26df95ff.pdforal argument transcript
Guide generated September 21, 2026. Automated validation accepted this version.