What is a Markush claim?

The Markush claim allows a patent drafter to select a particular element of the invention wherein that element may be selected from a group of elements all sharing some common characteristic.

What is a Markush grouping?

A Markush grouping is proper if the alternatives defined by the Markush group (i.e., alternatives from which a selection is to be made in the context of a combination or process, or alternative chemical compounds as a whole) share a “single structural similarity” and a common use.

What is Jepson claim?

A Jepson claim is one where the preamble makes some kind of statement that relates to the state of the prior art, and then claims an improvement over the prior art. Jepson format allows the patentee to use the preamble to recite elements or steps of the claimed invention which are conventional or known.

Can you use and/or in a patent claim?

Examiners often reject “and/or” in the claims as indefinite under Section 112. However, as noted above, it should be clear that there is nothing inherently indefinite about the term.

How is the Markush group patent claim construed?

Indeed, the court emphasized the overarching principle of claim construction: All patent claims, including Markush claims, must be construed in view of “the words of the claims, the specification, the prosecution history, and any relevant extrinsic evidence.”

How is claim language defined by a Markush grouping?

Claim language defined by a Markush grouping requires selection from a closed group “consisting of” the alternative members. Id. at 1280, 67 USPQ2d at 1196. See MPEP § 2111.03, subsection II, for a discussion of the term “consisting of” in the context of Markush groupings.

Why is the Markush group open to blends?

Id. at 1360-61. However, intrinsic evidence demonstrated that the Markush group was open to blends because one listed resin was a sub-type of another listed resin, overcoming the “presumption that a Markush group is closed to mixtures of the listed elements.” Id. at 1363-64.

When is a Markush claim rejected by a court?

A Markush claim may be rejected under judicially approved “improper Markush grouping” principles when the claim contains an improper grouping of alternatively useable members.