## Facts

- Enzo Biochem, Inc. owned U.S. Patent No. 4,900,659, directed to nucleic acid probes and detection methods for *Neisseria gonorrhoeae*.
- The patent sought probes that selectively hybridize to *N. gonorrhoeae* and distinguish it from *N. meningitidis*.
- The specification did not list complete nucleotide sequences for the claimed probes.
- The specification described probes by hybridization behavior and referred to deposits of relevant nucleic acid material with the ATCC.
- Enzo sued multiple defendants for infringement in the Southern District of New York.
- The district court granted summary judgment that claims 1–6 were invalid for failure to satisfy the written description requirement of 35 U.S.C. § 112 ¶ 1, reasoning that the sequences had to be disclosed in the specification text.
- On panel rehearing, the Federal Circuit vacated its earlier affirmance and reconsidered whether deposits and functional description could satisfy written description.

## Issues

1. Whether, for nucleic acid probe claims, written description under 35 U.S.C. § 112 ¶ 1 can be satisfied by reference in the specification to a publicly available biological deposit rather than reciting full nucleotide sequences.
2. Whether a functional description of nucleic acids (including defined selective hybridization characteristics) can contribute to satisfying written description.
3. Whether the adequacy of written description for genus claims covering variants and subsequences can be resolved as a matter of law on summary judgment on the existing record.

## Decision

- The Federal Circuit reversed the summary judgment of invalidity and remanded.
- The court held that a specification’s reference to a publicly accessible deposit may satisfy the written description requirement for genetic inventions.
- The court held that functional descriptions, including defined hybridization characteristics, may contribute to written description in appropriate circumstances.
- The court rejected a categorical rule that nucleic acid inventions require disclosure of the actual nucleotide sequences in the specification text to meet written description.
- The court directed further factual development on whether the disclosure supported the full scope of the claimed genus, including variants and subsequences.

## Legal Principles

- Written description is a distinct requirement under § 112 ¶ 1 focused on whether the inventor was in possession of the claimed invention as of the filing date.
- The adequacy of written description is evaluated case-by-case and depends on the nature and scope of what is claimed.
- Disclosure format is not rigid: where conventional textual description is impracticable, identifying and incorporating by reference a qualifying public deposit can place the invention in the public’s possession and can support written description.
- Functional characterization is not per se inadequate; when it meaningfully identifies the claimed nucleic acids to skilled artisans (e.g., via defined hybridization behavior and related conditions), it can support written description, especially when linked to representative examples or deposits.
- For genus claims, support for disclosed species does not automatically establish written description for the full genus; whether the disclosure reaches the breadth of claimed variants is a factual question that may preclude summary judgment.

## Conclusion

The Federal Circuit held that written description for nucleic acid probe claims is not limited to reciting sequences in the specification and may be satisfied by a combination of referenced public deposits and defined functional properties, while requiring a fact-specific inquiry into whether the disclosure supports the full breadth of the claimed genus.


Enzo Biochem, Inc. v. Gen-Probe Inc., 296 F.3d 1316 (Fed. Cir. 2002)