Patent-eligible subject matter — 35 USC §101 and Alice/Mayo
**35 USC §101:** 'Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent.'
**Judicial exceptions** — not patent-eligible: • Laws of nature • Natural phenomena • Abstract ideas (mathematical concepts, mental processes, methods of organizing human activity)
**Alice/Mayo framework (MPEP §2106):**
**Step 1** — Is the claim directed to one of the four statutory categories (process, machine, manufacture, composition)?
**Step 2A — Two-prong inquiry:** • Prong One: Does the claim recite a judicial exception? • Prong Two: If yes, does the claim recite additional elements that **integrate** the judicial exception into a **practical application** (improvement in computer/technology, particular treatment of a disease, etc.)?
**Step 2B** — If not integrated in 2A: Does the claim recite additional elements that amount to 'significantly more' than the exception? Well-understood, routine, conventional activity does NOT count.
**Key cases:** • *Alice Corp. v. CLS Bank* (2014) — computer implementation of abstract idea not enough. • *Mayo v. Prometheus* (2012) — natural correlation between metabolite level and dosage not patent-eligible; 'apply it' not enough. • *Myriad* (2013) — isolated DNA sequences same as natural; cDNA not natural and therefore eligible. • *Diehr* (1981) — software + physical transformation eligible.
**2019 PEG** (Patent Eligibility Guidance) and 2024 AI-PEG update apply the Alice/Mayo framework to AI/software inventions.