The USPTO’s “Guidance For Determining Subject Matter Eligibility Of Claims Reciting Or Involving Laws of Nature, Natural Phenomena, and Natural Products” has been criticized for requiring a product to be markedly different in structure from a product of nature in order to be eligible for patenting, even though the Supreme Court has considered both structure and function when evaluating the eligibility of a product derived from nature.  When questioned on this issue, PTO representatives admitted their difficulty understanding that a product could have a different function without having a different structure, and specifically asked the public to provide examples of such phenomena within the July 31, 2014 public comment period. How many examples can we provide where the function of a compound depends on the context?


Many vaccines are based on a protein present on the surface of the pathogen, such as a coat protein of a virus. In the context of the virus, the protein may protect the virus from the environment. Once isolated from the virus, the protein is useful as a vaccine, to induce antibodies that will protect the vaccinated subject from infection by the virus. Even better results may be afforded by a vaccine based on a fragment of the protein that more specifically induces protective antibodies.

So, vaccines are one example of compounds that can have the same structure but a different function depending on the context (pathogen vs. vaccine).

Small Molecule Drugs

Many small molecule drugs are isolated from plants or other natural sources (or are made synthetically after originally being discovered by isolating from a natural source). Such small molecules may have any number of functions in the plant, but once isolated from the plant and purified, are useful as drugs to treat patients suffering from a particular disease or condition.

So, small molecule drugs are another example of compounds that can have the same structure but a different function depending on the context (plant vs. drug).


Minerals may not perform any active function in their native state (other than contributing to the geological makeup of their surroundings), but can exhibit many different functions depending on the context in which they are used. For example, zinc oxide (which occurs naturally as zincite) has a high refractive index, high thermal conductivity, antibacterial properties and UV-absorbing properties. Thus, when zinc oxide is isolated and purified it can function as a sunscreen, as a pigment, or as a semi-conductor (to name a few), depending on the context.

So, minerals are yet another example of compounds that can have the same structure but vastly different functions depending on the context.


Many antibiotics are produced by microorganisms. Antibiotics may inhibit the growth of other microorganisms that threaten the viability of the producing microorganism. When antibiotics are isolated and purified from culture, they can be used to prevent or treat infection in other organisms, including farm animals, pets and humans.

So, antibiotics are an example of compounds that can have the same structure but vastly expanded function depending on the context.

Submit Your Examples By July 31

These are just a few examples of how a compound can exhibit a different function without having a different structure. Please help the USPTO understand this important principle by submitting your examples in written comments by July 31, 2014, by email to