Federal Circuit Adds “Method of Preparation” Claims to Bucket List of Claim Types that May Elude the Dreaded US 101 Invalidity Finding

March 20, 2020
By Melanie Szweras and Andrea Uetrecht

In the United States, ever since the 2012 Supreme Court decision in Mayo v. Prometheus, many diagnostic method claims have been found to be unpatentable on the basis that they are directed to a natural phenomenon or law of nature. In the Illumina, Inc. v. Ariosa Diagnostics, Inc. (Fed. Cir. 2020) [Illumina] decision released earlier this week, the Federal Circuit held that claims making use of a newly discovered natural phenomenon to prepare a sample for testing were not “directed to” a patent-ineligible concept.

The two patents at issue in Illumina relate to obtaining fetal DNA for genetic testing. The patents acknowledged that it was known that extracellular fetal DNA could be found in maternal plasma. The problem faced by the inventors was that the vast majority of circulating DNA is maternal DNA, making it difficult to conduct fetal genetic testing. The inventors discovered that the fetal DNA in circulation was much shorter than maternal DNA, which provided a solution to the problem. The invention made it possible to prepare a sample enriched for fetal DNA by separating and isolating circulating DNA fragments that are smaller than 500 base pairs. This enriched fraction could then be used for fetal genetic testing.

The majority of the panel was quick to point out that the claims before them did not fall into the diagnostic “bucket” but instead belong to a “method of preparation” bucket. This distinction led the majority to conclude that the claims were directed to a patent-eligible method that made use of the newly discovered natural phenomenon, not the natural phenomenon itself. The concrete steps provided in the claims, although conventional and routine in themselves, result in a fraction that is different from the naturally-occurring fraction. The court also pointed out that this is different from claims that merely detect a natural phenomenon.

The dissenting judge took the view that, because the “claimed advance” was a natural phenomenon, the claims themselves were in fact directed to a patent-ineligible natural phenomenon. The approach taken by the dissenting judge highlights the problems with the Mayo framework – so long as there is a “natural phenomenon” underpinning a new and useful invention, and the steps to achieve it are routine and conventional, the court struggles to recognize that any application of a new discovery could constitute patentable subject matter.

Going forward it will be important for applicants that have made a discovery that may be susceptible to being rejected as a natural phenomenon to consider adding claims that position the invention as a method of preparation. As with investing, it’s important not to put all your eggs in the same basket. Or should we say bucket?

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