Counsel for Myriad emphasized that isolated DNA does not exist in nature, and is therefore patentable, in much the same way a baseball bat made from the wood of a tree would be patentable.
Counsel for the plaintiffs focused on the sequence similarities between isolated DNA and chromosomal DNA, disregarding the physical and chemical differences between them, in presenting his position that isolated DNA are products of nature and should not be eligible for patent.
Interestingly, the Solicitor General also appeared, and argued on behalf of U.S. government that if the sequence of the isolated DNA could be found in chromosomal DNA, then it is a product of nature and should not be patent eligible. This position differs from that of his earlier brief, in which he asserted cDNA should be patent eligible since it is synthetic and not found in nature. The Solicitor General urged that merely isolating a substance does not constitute human invention.
The panel of judges hearing arguments in this case, comprising Judges Lourie, Bryson, and Moore, asked cogent questions indicating their grasp of the underlying science and/or technology. For instance, counsel was asked to distinguish between isolating a substance, such as DNA from a chromosome, which requires breaking bonds binding the substance to its surroundings, from purifying a substance, such as by washing it with a solvent to remove impurities. Notably, Judge Moore acknowledged that the U.S. Patent & Trademark Office (USPTO) has been granting isolated gene patents for over 35 years, and that the USPTO guidelines expressly cite isolated genomic DNA as being patent-eligible subject matter. It is therefore odd that the U.S. government would take a position against the USPTO, which is part of the executive branch, and that they would be willing to overlook years of precedent.