Genus and Species

Genus and Species. When dealing with anticipation in patent law one of the more difficult concepts to deal with is when genus can anticipate species.

Recently a first year law student wrote me and admitted he was having a difficult time getting his head around the genus and species distinction in analyzing the novelty of claims and asked if I could explain it in simple language. My first paragraph in answering him was "Don’t feel bad about being confused about genus and species distinctions. It is a complex and subjective subject."

So what is going on here? Let's start from scratch because many readers of this site are not that familiar with all aspects of patent novelty issues. To begin with let's define some terms. The terms genus and species obviously seems to come from biology. As applied in patent claims think of the terms general (genus) and specific (species). To use a chemistry example a genus might be "acids" and a species of that might be "acetic acid". So the issue that comes up in staking out the metes and bounds of what a claim covers is questions like 1) if I disclose the use of "acids" does that mean a later patent cannot claim "acetic acid" and 2) if I disclose "acetic acid" does that mean a later patent cannot claim "acids" in general.

A very simple answer to that is that a species disclosed in the prior art will always anticipate a claimed genus. I know of no exceptions to that. So if I disclose the use of "acetic acid" for my particular invention you cannot come along later in a similar invention and claim the use of "acids" in general. The basic reason for this result is that once a species is disclosed then claiming a genus is again claiming the species – which should not be allowed. Think about that for a minute and you will see the logic of it. If I have already disclosed the use of "acetic acid" then when you try to claim the more general term "acids" you are also claiming the use of "acetic acid", but you cannot do that because i have already disclosed that, so it is "anticipated".

If you accept that as relatively easy to understand then let's talk about the reverse case. The reverse case is much more complicated. We are now talking about an example where I have disclosed the use of "acids" and you want to claim the use of "acetic acid". Generally speaking, the disclosure of a large genus rarely anticipates a narrowly claimed species, while a small genus can anticipate a claimed species. But what constitutes large (or small)? The courts have ruled that someone disclosing only a genus (and that genus is large) is not really disclosing or teaching that a particular species is especially critical in another invention. If I disclose a formula that includes “acids” and you come along later an develop a formula that only works with acetic acid then I did not really anticipate your invention. The rub comes when the the genus is small. In some cases the courts have ruled that if a person having ordinary skill in the art (PHOSITA) reads a reference to a genus and “can immediately envisage each and every member of the sub-genus” then she is being taught that each species will work.

Does genus and species sound subjective? Welcome to claim interpretation.

Where does all of this come from? The first paragraph of 35 U.S.C. § 112 requires that the “specification shall contain a written description of the invention.” To be adequate, the written description must describe the claimed invention in sufficient detail for one skilled in the art to reasonably conclude that the inventor had possession of the claimed invention at the time the patent application was filed. Using this requirement, the Federal Circuit has held that claims directed to a broad genus may not be adequately supported when the applicant describes only a small number of species. In particular, in such a case, it may be unclear whether the applicant was actually in possession of any of the remaining species at the time of filing.

Bottom line - you need to be aware of genus and species issues when dealing with possible anticipation from the prior art.



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