Patentable Subject Matter Eligibility – Nature-Based Products

July 2015

Since the Supreme Court decisions in Mayo1 and Myriad2, the United States Patent and Trademark Office (USPTO) has issued several iterations of guidance regarding subject matter eligibility with respect to laws of nature and nature-based products. The latest guidance, along with some examples, was issued on December 16, 2014 and can be found here. Additional explanatory examples specific to nature-based products were posted by the USPTO in February 2015. These examples can be found here.

Differences from previous guidance

This latest guidance was intended to be more straightforward than the previous March 2014 guidelines3 and was based in part on the Supreme Court decision in Alice4 of June 2014, as well as comments received from the public on the previous guidelines. The December 2014 guidance supersedes that of March 2014 and is different in a few key aspects:

  • For nature-based products, an analysis of whether a claim amounts to “significantly more” than a product of nature exception is no longer relevant for claims that do not recite such an exception;
  • The previous guidance required an analysis of whether a judicial exception applied to a claim if the claim “involved” one or more exceptions while in contrast, the current guidance requires this type of analysis only if a claim is “directed to” an exception. The USPTO defined “directed to” as having a narrower meaning than merely “involving.” Claims “directed to” a judicial exception are those that recite the exception, i.e., set forth or describe the exception; and
  • The test for determining whether a nature-based product is “markedly different” from its naturally occurring counterpart now includes not only structure, but also function and/or other properties.

Two-step analysis

The December 2014 guidance includes a two-step analysis. Step 1 asks whether the claimed subject matter is a process, machine, manufacture, or composition of matter. If the answer is no, then the claim is ineligible under 35 U.S.C. § 101. If the answer is yes, the analysis proceeds to Step 2A.

Step 2A asks whether the claim is directed to a law of nature, a natural phenomenon, or an abstract idea. Essentially, this step asks whether a judicially recognized exception applies. A product of nature, for example, is considered to be a judicially recognized exception because it ties up the use of naturally occurring objects. With respect to claims reciting a nature-based product, Step 2A boils down to the question of whether the nature-based product is “markedly different” from its naturally occurring counterpart. If there is no marked difference, the claim is directed to an exception. A more detailed discussion of what constitutes “markedly different” is presented below. If the answer to Step 2A is no (the claim is not directed to an exception, e.g., the nature-based product is markedly different), then the claim qualifies as eligible subject matter, and there is no need to proceed to the next step. However, if the answer to Step 2A is yes (the claim is directed to an exception), the analysis proceeds to Step 2B.

Step 2B asks whether the claim recites additional elements that amount to “significantly more” than the exception. If the answer to Step 2B is yes, the claim qualifies as eligible subject matter; if the answer is no, the claim is ineligible under 35 U.S.C. § 101.

“Markedly different” as applied to nature-based products

The “markedly different” test is used in Step 2A of the analysis to evaluate not all limitations of a claim but only the nature-based product limitations. This test compares the nature-based product with its naturally occurring counterpart, or if one does not exist, the closest naturally occurring counterpart. For example, where a nature-based product is a combination of naturally occurring components, a comparison is made between the combination and the individual components.

Structure as well as non-structural properties, such as function, and/or other properties can be used as evidence of markedly different characteristics. The USPTO noted the following non-limiting examples of types of characteristics that can be considered in making this determination:

  • Structure or form, e.g., physical, chemical, or genetic structure/form;
  • Physical or chemical properties;
  • Pharmacological or biological functions or activities; and
  • Phenotype, e.g., functional/structural characteristics.

Of note, if a characteristic of the nature-based product is merely an inherent characteristic of the naturally occurring counterpart, or a difference that arose independently of an Applicant’s efforts, the nature-based product is not considered to be markedly different.

To illustrate application of the “markedly different” test, a summary of the explanatory examples issued by the USPTO in February 2015 is presented below.

Small molecules

In a claim to “purified amazonic acid,” the purified amazonic acid would not be markedly different from its natural counterpart because it is not structurally different from naturally existing amazonic acid (found in tree leaves) and there is no indication that it has differences in function or other properties.

However, “deoxyamazonic acid” in a claim would be markedly different from its natural counterpart (amazonic acid) because even if there is no indication of a difference in function, the claimed compound is structurally distinct from amazonic acid. Thus, the claim would be subject matter-eligible.

Bacterial mixtures

In a claim directed to a bacterial mixture containing several strains of Rhizobium that are unaffected by each other with respect to their ability to infect specific plants, the nature-based product (mixture of Rhizobium) is compared to its natural counterpart (the individual strains of Rhizobium). The combination would not be markedly different from the individual strains because there is no indication of a difference in function (no difference in specificity of plant infectivity), structure (mere aggregation of strains does not change the structure of each individual strain), or other properties.

However, in a claim directed to a bacterial mixture containing two strains—Rhizobium californiana and Rhizobium phaseoli—where the specification indicates that the mixture of these two specific strains has characteristics different from each strain individually, and the mixture is not normally found in nature, such a bacterial mixture would be markedly different from naturally occurring bacteria. In particular, although there is no structural difference, the difference in function (mixing strain 1 with strain 2 changed the natural infectivity of strain 1) is sufficient to constitute a marked difference. Thus, the claim would be subject matter-eligible.


In a claim to an “antibody to Protein S,” where additional limitations are not present in the claim, and where naturally occurring antibodies to Protein S have been discovered in mice and coyotes, the claimed antibody would not be markedly different from naturally occurring antibodies to Protein S. There is no difference in function (binding to Protein S) or structure (the claim scope is broad enough to encompass antibodies structurally identical to those that are naturally occurring).

However, if the claim had included the limitation that the antibody “comprises complementarity determining region (CDR) sequences set forth as SEQ ID NOs: 7-12,” then such an antibody would be markedly different from a naturally occurring antibody to Protein S. The different CDRs confer a difference in structure, and there may also be a difference in function (binding epitope). Thus, the claim would be subject matter-eligible.

According to the USPTO guidelines, there are some situations in which the “markedly different” test does not apply. A process claim is not subject to the test, unless it is drafted such that it is essentially no different from an equivalent product claim. As an example, a process claim directed to “a method of providing an apple” would be essentially no different from a claim directed to “an apple” and would thus be subject to the “markedly different” test.

In some cases, a streamlined eligibility analysis may apply in place of the “markedly different” test for Step 2A if the claim, when viewed as a whole, clearly does not tie up a judicial exception. In other words, if the claim sufficiently limits the judicial exception such that others, e.g., the general public, are not prevented from all uses/applications of the exception, then the claim may qualify as subject matter-eligible without needing to proceed through the full eligibility analysis. For example, a claim directed to an artificial hip prosthesis coated with a naturally occurring mineral does not tie up the naturally occurring mineral to the extent of preventing others from all uses of the mineral. Therefore, such a claim would be found subject matter-eligible based on this streamlined eligibility analysis.

As a further example of the streamlined analysis, a claim directed to a “method of treating breast or colon cancer, comprising: administering an effective amount of purified amazonic acid to a patient suffering from breast or colon cancer” would not be directed to an exception. Although the claim recites a nature-based product (purified amazonic acid), it is not directed solely to the product and does not tie up all uses of the product. Thus, such a claim would be subject matter-eligible based on the streamlined eligibility analysis.

“Significantly more”

Unlike the “markedly different test” that involves only those limitations directed to a nature-based product, the “significantly more” test in Step 2B is performed in consideration of the claim as a whole. While no bright line rules have been presented regarding what constitutes “significantly more,” the USPTO has listed a few exemplary limitations that would amount to “significantly more” than a judicial exception, such as:

  • Improving another technology or technical field;
  • Causing a transformation or reduction of a particular article to a different state or thing;
  • Adding an unconventional step or a specific limitation that is not well understood, routine or conventional.

According to the USPTO guidance, presenting limitations that merely add the words “apply it” to the judicial exception, or adding non-specific routine/conventional steps to the judicial exception, does not amount to significantly more than the exception.

In the hypothetical claim above to “purified amazonic acid,” there are no additional claimed features that would add significantly more to the judicial exception. Thus, such a claim would be directed to ineligible subject matter.

This latest USPTO guidance further defines the standards to be applied by Examiners in making a subject matter eligibility determination with respect to nature-based products and offers an additional resource for practitioners attempting to rebut related rejections. The USPTO has solicited comments from the public on the guidelines and may issue a revised version in the future. Additional clarity will also be provided by subsequent court decisions. For example, the Federal Circuit stated in the recent Sequenom decision that “[w]here claims of a method patent are directed to an application that starts and ends with a naturally occurring phenomenon, the patent fails to disclose patent eligible subject matter if the methods themselves are conventional, routine and well understood application in the art” and that “[w]hile preemption may signal patent ineligible subject matter, the absence of complete preemption does not demonstrate patent eligibility.”5

1  Mayo Collaborative Serv. v. Prometheus Labs., Inc., 566 U.S. __, 132 S. Ct. 2107 (2013).
2  Association for Molecular Pathology v. Myriad Genetics, Inc., 569 U.S. __, 133 S. Ct. 2107 (2013).
3  Procedure For Subject Matter Eligibility Analysis Of Claims Reciting Or Involving Laws Of Nature/Natural Principles, Natural Phenomena, And/Or Natural Products (March 2014).
4  Alice Corp. Pty. Ltd. v. CLS Bank Int’l, 573 U.S. 134 S. Ct. 2347 (2014).
5  See Ariosa Diagnostics v. Sequenom, Inc. (Fed. Cir. June 12, 2015) (holding methods of prenatal diagnosis by detecting cell free fetal DNA in maternal blood not patent eligible).