- "isolated" DNA molecules do not exist in nature, and therefore are patent-eligible subject matter under 35 USC 101
- Myriad's claims to a method for screening potential cancer therapeutics via changes in cell growth rates is not merely a scientific principal, and therefore are patent-eligible under 35 USC 101
- Myriad's method claims directed to "comparing" and "analyzing" DNA sequences are not sufficiently transformative, and cover only ineligible abstract mental steps
Relying significantly on U.S. Supreme Court precedent, the Federal Circuit majority opinion explained that "isolated" DNA claims are patentable subject matter since they cover molecules that are "markedly different - have a distinctive chemical identity and nature - from molecules that exist in nature." They stated that it was undisputed that isolated DNA as claimed by Myriad exists in a different chemical form (a distinctive chemical molecule) from native DNA as it exists in the body, correctly highlighting that native DNA molecules are part of a contiguous string of DNA located on a chromosome, and further complexed with histones and packaged into chromatin. Isolated DNA, on the other hand, is a free-standing portion of DNA, frequently only a single gene, and is the product of human intervention, such as by cleaving the covalent bonds of the native DNA backbone or synthesizing a DNA molecule. They emphasize that isolating is not the same as purifying -- purification makes pure a material that was previously impure, whereas isolating DNA requires removing it from its native cellular and chromosomal environment, producing a molecule that is markedly different from what exists in the body. They rejected AMP's argument that having the same nucleotide sequence renders an isolated DNA molecule the same as that found in nature. They also rejected the government's argument that only cDNA's should be patent eligible, finding that both cDNA's and isolated DNA molecules are patent eligible. They also noted their decision agrees with the long-standing practice of the U.S. Patent & Trademark Office.
With regard to the method claims, the Court found that the steps of "comparing" or "analyzing" gene sequences can be accomplished with mere inspection alone, and so are only abstract mental processes and are ineligible for patent protection. They do note, however, that applications of such abstract mental processes may be patentable, but the claims at issue were not directed to applications. The claims for a method of screening potential cancer therapeutics was held to be patent eligible, since it involved the transformative steps of "growing" transformed cells in specific conditions (requiring manipulation), and "determining" the cells' growth rates (also involving physical manipulation).
The decision was not unanimous, however. Of the three-judge panel, Judge Bryson dissented with regard to "isolated" DNA claims, stating that he believed there was no difference between them and native genes. He did agree that cDNA's are patent eligible.