How does the MPEP address the anticipation of Markush claims?
How does the MPEP address the anticipation of Markush claims?
The Manual of Patent Examining Procedure (MPEP) provides specific guidance on the anticipation of Markush claims in MPEP 2131.02. Markush claims are a unique type of claim that lists alternative members in a single claim.
According to the MPEP:
“A reference disclosure can anticipate a claim even if the reference does not describe ‘the limitations arranged or combined as in the claim, if a person of skill in the art, reading the reference, would ‘at once envisage’ the claimed arrangement or combination.” (Kennametal, Inc. v. Ingersoll Cutting Tool Co., 780 F.3d 1376, 1381, 114 USPQ2d 1250, 1254 (Fed. Cir. 2015)).
This means that for a Markush claim to be anticipated, the prior art doesn’t need to disclose every alternative member listed in the claim. If the prior art discloses one of the alternative members, it can anticipate the entire Markush claim.
For example, if a Markush claim lists “a material selected from the group consisting of copper, silver, and gold,” a prior art reference that discloses the use of copper would anticipate the entire claim, even if it doesn’t mention silver or gold.
Examiners should carefully analyze Markush claims and compare them with prior art disclosures to determine if anticipation has occurred, keeping in mind that disclosure of a single alternative can be sufficient for anticipation.
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