A day after the United States Supreme Court delivered its decision in Mayo Collaborative Services v. Prometheus Laboratories, Inc., the United States Patent and Trademark Office issued preliminary guidance instructing examiners to reject process claims that invoke laws of nature and only add steps which constitute "well-understood, routine, conventional activity" that is described in the most general of terms regardless of whether there is a transformation involved.

According to the Patent Office, although the "machine or transformation test" remains an "important and useful clue," it is not to be considered "the sole or a determinative test" for eligibility as it does not "trump the 'law of nature' exclusion." Moreover, the Mayo decision reinforces the need for a patent applicant whose claims include a law of nature, a natural phenomenon, or an abstract idea to ensure the "claimed product or process amounts to significantly more than a law of nature, a natural phenomenon, or an abstract idea with conventional steps specified at a high level of generality appended thereto." (emphasis in original). Although the guidelines put special importance on process claims as were at stake in Mayo, the guidelines appear to indicate this analysis may apply to all claims related to laws of nature, natural phenomena, or abstract ideas.