## Facts

- Patent applicants sought claims to isolated and purified DNA and cDNA molecules encoding certain heparin-binding growth factors (HBGFs), proteins associated with mitogenic activity.
- Claims included (1) specific cDNA molecules encoding particular HBGFs and (2) broader claims covering all DNA molecules encoding the disclosed proteins.
- The examiner rejected claims 4–7 as obvious under 35 U.S.C. § 103, and the Board of Patent Appeals and Interferences affirmed.
- The Patent Office relied primarily on: (1) a reference disclosing a related heparin-binding protein and its amino-acid sequence (but no DNA sequence) and describing it as brain-specific, and (2) a molecular biology manual describing general gene-cloning techniques.
- The Board reasoned that because gene cloning techniques were well known, disclosure of the protein sequence rendered the gene effectively accessible and therefore the claimed DNA/cDNA molecules obvious.
- The applicants appealed to the United States Court of Appeals for the Federal Circuit.

## Issues

1. Whether claimed DNA/cDNA molecules are prima facie obvious under § 103 when the prior art discloses the corresponding protein (or its amino-acid sequence) and general cloning methods, but does not disclose or suggest the specific nucleotide sequences claimed.
2. Whether a “structurally new” chemical entity can be held obvious without prior-art teaching or suggestion of the claimed structure.

## Decision

- The Federal Circuit reversed the Board’s affirmance of the § 103 rejections.
- The court held the Board erred in concluding the specific cDNA claims were obvious over the protein disclosure plus general cloning methods.
- The court found no record support for rejecting the broader DNA claims covering all DNA molecules encoding the disclosed proteins.
- The court rejected the Board’s premise that a protein disclosure and routine cloning techniques place the corresponding gene “in the public domain” for obviousness purposes.

## Legal Principles

- A prima facie case of obviousness for a structurally new chemical entity requires prior-art teachings that suggest the claimed compounds to a person of ordinary skill in the art.
- A DNA molecule is a distinct chemical structure; the mere fact that it encodes a known protein does not, without more, suggest the specific nucleotide sequence claimed.
- Because of the degeneracy of the genetic code, a known amino-acid sequence does not uniquely determine a single DNA sequence; this undermines an inference that any particular encoding DNA is obvious from the protein sequence alone.
- The existence of a general method for isolating or cloning DNA does not, by itself, establish obviousness of specific DNA molecules absent a suggestion or teaching directed to the claimed sequences.
- A prior-art description that limits a protein to a particular tissue can weigh against a finding of motivation to pursue the applicants’ targets.

## Conclusion

The Federal Circuit held that disclosure of a protein (or its amino-acid sequence), combined with routine gene-cloning methods, did not make specific encoding DNA/cDNA sequences obvious under § 103 absent prior-art suggestion of the claimed nucleotide structures, and it reversed the Patent Office’s rejection of claims 4–7.


In re Deuel, 51 F.3d 1552 (Fed. Cir. 1995)