If there is doubt as to whether a particular claim term is an accurate descriptor for the limitation at issue, it is probably best to use a more generic or even functional term, rather than a scientific term with an accepted meaning that may not be accurate. A court is unlikely to save the patentee from erroneous claim language (especially if the patentee was given ample opportunity to correct the error during prosecution).
Background / Facts: The patent at issue here concerns genetically modifying plants in order to confer resistance to a commonly used herbicide by inserting into plant cells a particular DNA segment containing the sequence of nucleotides identified as the gene coding for a particular enzyme. Although the underlying science was still being verified, the patent used the term “monooxygenase” throughout the specification and claims to characterize the enzyme whose gene was being coded. As it turns out, while the application was still pending, scientists determined that it was incorrect to refer to the enzyme as a monooxygenase, and that it was instead a dioxygenase. Yet, the patentee did not alter the claims of its application, even though the application did not mature into a patent until seven years after this discovery.
Issue(s): Whether the claim limitation “biological activity of 2,4-D monooxygenase” should be given a broad functional-based construction to cover the dioxygenase class of enzymes to which the lone working embodiment belongs.
Holding(s): No. The court noted that the patentee “chose the language based on an unverified belief that it accurately described its enzyme, learned that the belief was false while its application was pending, had seven years before its patent issued to alter the language, but never did.” Citing the “[f]amiliar claim-construction policies regarding public notice and patentee drafting duties,” the court determined that “there is no clear message that the patent gives … broad meaning to ‘2,4-D monooxygenase’ in place of the term’s accepted scientific meaning, which describes a particular mechanism of action.” The court therefore declined to remediate what it saw as negligent claim drafting at best. “Perhaps [the patentee] should have recognized that its background assumption that ‘mono’ was accurate was unverified, and initially used a different phrase.”