2117 Markush Claims
|
I. MARKUSH CLAIM
A “Markush” claim recites a list of alternatively useable members.
The listing of specified alternatives within a Markush claim is referred to as a Markush group or a Markush grouping.
Treatment of claims reciting alternatives is not governed by the particular format used (e.g., alternatives may be set forth as “a material selected from the group consisting of A, B, or C” or “wherein the material is A, B, or C”).
Although the term “Markush claim” is used throughout the MPEP, any claim that recites alternatively usable members, regardless of format, should be treated as a Markush claim.
II. DETERMINE WHETHER MARKUSH GROUPING IS PROPER
A Markush claim may be rejected under judicially approved “improper Markush grouping” principles when the claim contains an improper grouping of alternatively useable members.
A Markush claim contains an “improper Markush grouping” if either:
- (1) the members of the Markush group do not share a “single structural similarity” or
- (2) the members do not share a common use.
A. “Single Structural Similarity” - Members of a Physical, Chemical, or Art-Recognized Class; Common Use Includes Functional Equivalence
Members of a Markush group share a “single structural similarity” when they belong to the same recognized physical or chemical class or to the same art-recognized class (prong 1) and the members of a Markush group share a common function or use when they are disclosed in the specification or known in the art to be functionally equivalent (prong 2).
B. “Single Structural Similarity” - Substantial Structural Feature; Common Use Flows From Substantial Structural Feature
Where a Markush grouping describes alternative chemical compounds, whether by words or chemical formulas, and the alternatives do not belong to a recognized class as explained in subsection II.A, above, the members of the Markush grouping may be considered to share a “single structural similarity” and common use where the alternatives share a substantial structural feature that is essential to a common use.
III. REJECTION BASED ON IMPROPER MARKUSH GROUPING
When an examiner determines that the members of a Markush group lack either a single structural similarity or a common use, or if the single structural similarity is a substantial structural feature of a chemical compound that is not essential to the common use, then a rejection on the basis that the claim contains an “improper Markush grouping” is appropriate (see subsection II).
