How should a Markush group be properly formatted in a patent claim?
A Markush group in a patent claim should be formatted as a closed group of alternatives. According to the MPEP 2173.05(h):
“A Markush grouping is a closed group of alternatives, i.e., the selection is made from a group ‘consisting of’ (rather than ‘comprising’ or ‘including’) the alternative members.”
The MPEP also notes that the specific format used is not critical, providing examples:
- “a material selected from the group consisting of A, B, and C”
- “wherein the material is A, B, or C”
It’s important to use closed language to clearly define the scope of the alternatives.
To learn more:
Topics:
MPEP 2100 - Patentability,
MPEP 2173.05(H) - Alternative Limitations,
Patent Law,
Patent Procedure