In Ariosa Diagnostics v. Sequenom, the U.S. Court of Appeals for the Federal Circuit invalidated Sequenom’s patent on a prenatal test that detected fetal DNA in a pregnant woman’s blood, holding that the claims covered a natural phenomenon applied only through routine laboratory steps, and the Supreme Court refused to hear the appeal in 2016.1Justia. Ariosa Diagnostics, Inc. v. Sequenom, Inc.2Supreme Court. Docket for 15-1182
The Patent and the Dispute
Sequenom held U.S. Patent No. 6,258,540, which covered a method for prenatal screening based on cell-free fetal DNA circulating in the plasma and serum of pregnant women. Before the inventors’ work, that genetic material was treated as waste in blood samples. They developed a way to isolate it and read paternally inherited sequences from a maternal blood draw, allowing screening for fetal genetic conditions without the risks of invasive sampling.1Justia. Ariosa Diagnostics, Inc. v. Sequenom, Inc.
Ariosa Diagnostics and other diagnostic companies sought a declaration that their prenatal tests did not infringe the patent. Sequenom had been enforcing its rights against several firms in the field. The dispute moved to the Federal Circuit, which reviews patent appeals, and turned on whether the patent claimed something eligible for protection at all.1Justia. Ariosa Diagnostics, Inc. v. Sequenom, Inc.
Why the Federal Circuit Invalidated the Claims
The court applied the two-step test from Mayo and Alice. Section 101 of the Patent Act allows patents on new and useful processes, machines, manufactures, and compositions of matter, but courts have long held that laws of nature, natural phenomena, and abstract ideas fall outside that grant.3GovInfo. 35 U.S.C. § 1014USPTO. 2024 Guidance on Patent Subject Matter Eligibility
At step one, the court found the claims directed to a natural phenomenon. Cell-free fetal DNA exists in maternal blood on its own; the inventors discovered it there, but they did not create it. The claimed method began and ended with that naturally occurring material.1Justia. Ariosa Diagnostics, Inc. v. Sequenom, Inc.
At step two, the court asked whether the remaining steps added an inventive concept sufficient to transform the natural phenomenon into a patent-eligible application. They did not. Preparing plasma or serum, amplifying DNA by polymerase chain reaction, and detecting sequences were, in the court’s view, routine and well-understood techniques in molecular biology at the time of the invention. Applying conventional methods to a newly recognized biological fact was not enough.1Justia. Ariosa Diagnostics, Inc. v. Sequenom, Inc.
The judges acknowledged the medical value of the discovery but said Supreme Court precedent compelled the result. The specific claims at issue were invalid under Section 101.1Justia. Ariosa Diagnostics, Inc. v. Sequenom, Inc.
The Supreme Court’s Refusal to Review
Sequenom petitioned the Supreme Court for a writ of certiorari. In 2016, the Court denied the petition, leaving the Federal Circuit’s decision in place as the final word on the patent.2Supreme Court. Docket for 15-1182
What the Decision Means for Diagnostic Patents
The ruling set a demanding line for diagnostic method patents built on biological discoveries. Identifying a previously unknown natural correlation, even one with clear clinical value, does not by itself yield a patentable invention. The claim has to include something beyond the discovery: an unconventional technique, a genuinely new application, or steps that go past what skilled workers in the field were already doing.1Justia. Ariosa Diagnostics, Inc. v. Sequenom, Inc.4USPTO. 2024 Guidance on Patent Subject Matter Eligibility
For companies developing tests that read natural biomarkers, the case remains a working reference point on how the Federal Circuit applies the Mayo/Alice framework to methods that pair a natural phenomenon with standard laboratory tools.