What can — and can't — be patented?

Yes. A new, non-obvious, useful chemical compound or formulation is squarely patentable subject matter.

Example · A newly synthesized molecule, or a novel formulation of a known drug, is classic eligible subject matter.

Rule · New compositions of matter made by people are eligible under §101.

Yes. Machines, mechanical devices, and physical apparatus are core patentable subject matter.

Example · A new engine component, surgical instrument, or consumer gadget mechanism.

Rule · Machines and manufactures are two of the four statutory categories.

Yes. A novel, non-obvious process that transforms materials into a different state or thing is eligible.

Example · The rubber-curing process in Diamond v. Diehr — even though it used a math formula.

Rule · Processes are a statutory category; transformation of an article is a strong signal.

Yes — but through a design patent, which protects ornamental appearance, not a utility patent.

Example · The shape of a bottle or the graphical layout of an icon — protected by a design patent for 15 years from grant.

Rule · Ornamental designs are eligible under the separate design-patent statute (§171).

Yes. A distinct, new plant variety reproduced asexually can be protected by a plant patent.

Example · A new cultivar of rose or apple, propagated by cuttings or grafting.

Rule · Asexually-reproduced plant varieties are eligible under the plant-patent statute (§161).

Yes — if the claim is tied to a specific technical improvement, not just an abstract idea running on a generic computer.

Example · A new data structure that makes a database faster (eligible, like Enfish) versus 'use a computer to manage escrow' (ineligible, like Alice).

Rule · Alice step one: is it directed to an abstract idea, or to an improvement in technology?

Difficult. A pure method of organizing human activity is an abstract idea; it needs a genuine technical component to survive.

Example · Hedging risk was ineligible in Bilski v. Kappos. A method that also solves a concrete technical problem stands a better chance.

Rule · Methods of organizing human activity are abstract ideas under the 2019 PEG.

You can't patent the idea — only a specific, novel, non-obvious technical implementation of it.

Example · 'An app that connects dog walkers' is an unprotectable idea; a new technical mechanism inside it might be patentable.

Rule · Ideas and results are not patentable; concrete implementations can be.

Yes, when claimed as a specific technical application or improvement — not as the abstract math of the model itself.

Example · A novel training technique that improves hardware efficiency is more defensible than 'a neural network that predicts X.'

Rule · The model's math is abstract; a concrete technical use can supply eligibility.

Isolated, naturally-occurring DNA is not patentable; synthetic cDNA and engineered sequences are.

Example · In AMP v. Myriad, isolated BRCA genes were ineligible products of nature, but lab-made cDNA was eligible.

Rule · Products of nature are excluded; human-made variants with new characteristics are not.

Rarely as a recipe. A simple list of ingredients is usually obvious; a genuinely novel composition or process can qualify.

Example · An ordinary recipe fails on obviousness; a new shelf-stable formulation or a non-obvious process may pass.

Rule · Eligible in principle, but recipes usually fail novelty (§102) or non-obviousness (§103).

Not on its own. A mathematical algorithm or formula claimed in the abstract is a classic judicial exception.

Example · Converting numbers between formats was unpatentable in Gottschalk v. Benson — but applying a formula to cure rubber was eligible in Diehr.

Rule · Mathematical concepts are abstract ideas; eligibility needs a practical application.

Usually not. A method that just detects a natural correlation, using conventional steps, is ineligible.

Example · Correlating metabolite levels with dosage was ineligible in Mayo v. Prometheus.

Rule · Laws of nature plus routine, conventional steps are not patentable.

No. Laws of nature, natural phenomena, and abstract scientific truths belong to everyone.

Example · You could not patent E=mc², gravity, or a newly-discovered natural correlation by itself.

Rule · Laws of nature and natural phenomena are core judicial exceptions.