Patent bar Patent eligibility and utility (35 U.S.C. 101) question: applicant claims an isolated bacterium of species S

Patent barPatent eligibility and utility (35 U.S.C. 101)

An applicant claims 'an isolated bacterium of species S' that is identical in structure and function to the bacterium as found in soil, merely separated from it. Under the USPTO's analysis, how is the claim treated?

A As eligible, because living organisms can always be patented
B As eligible, because isolation is a human act
C As a product of nature lacking marked differences
D As ineligible only if the bacterium has been patented before
E As eligible, because bacteria are compositions of matter

Show the answer and explanation

Answer: C. As a product of nature lacking marked differences

Answer: As a product of nature lacking marked differences. A nature-based product is a judicial exception unless it has markedly different characteristics from its naturally occurring counterpart (Chakrabarty; Myriad). Mere isolation without any change in structure, function or other properties does not create a marked difference (MPEP 2106.04(b), 2106.04(c)). Why not the others: - Isolation is human: isolation alone does not change the product's characteristics. - Living organisms always patentable: a man-made organism with markedly different characteristics can be, but not a natural one. - Composition of matter: passing Step 1 does not avoid the judicial exception. - Previously patented: prior patents do not affect the eligibility analysis. Rule: Natural products are eligible only with markedly different characteristics. Source: MPEP § 2105, § 2106.04(b)-(c) (9th ed., Rev. 01.2024); 35 U.S.C. 101; as at Oct 2026

Common mistake

Thinking isolation alone makes a natural product patentable.

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Original study material written from the MPEP; not a question from the current exam.Independent. Not affiliated with or endorsed by the USPTO. Verify figures and rules against current guidance before relying on them.