Negative Claim Leads to “Udder” Failure

Judge Rich gave us the adage, “the name of the game is the claim.” Given the number of cases issued by the Federal Circuit on written description, perhaps the adage should be revised as “the name of the game is the claim – supported by the specification.”

In In Re Bimeda Research & Development Ltd., the Federal Circuit issued another decision requiring the entire scope of the claims to be supported by the disclosure. While this is nothing new in patent law, the claim at issue is a negative claim that expressly excluded an element. The original claim was directed to a prophylactic method to treat infections in cow mammary glands by providing a physical barrier to the teat canal. During reexamination, the examiner rejected this claim, which was canceled and reintroduced to include the limitation that the sealed teat canal contained an acriflavine free formulation. The patent holder, Bimeda, argued that the specification generally describes exclusion of all anti-infectives and although acriflavine, was not specifically identified, one skilled in the art would understand the disclosure to exclude acriflavine because it was a well known antiseptic for treating cow mammary gland infections. The examiner and Board rejected this argument and the Federal Circuit agreed holding that the patent disclosure did not disclose the full scope of the new claim. By specifically excluding acriflavine, the implication was that other anti-infective agents could be included. The specification however, failed to support this implication as the stated intent of the claimed invention was to avoid use of all antibiotic agents.

Negative claims are unpopular in claim drafting. This case illustrates one drawback which is that an inverse interpretation of the claim can vastly expand the scope of possible alternates not contemplated by the disclosure