What is the “upon finding allowable subject matter” rule in Markush claim examination?

The “upon finding allowable subject matter” rule in Markush claim examination refers to the process where an examiner, upon finding allowable subject matter, extends the search to all members of the Markush group. This is explained in MPEP 803.02:

“If the examiner determines that the elected species is allowable, the examination of the Markush claim will be extended. If prior art is then found that anticipates or renders obvious the Markush claim with respect to a nonelected species, the Markush claim shall be rejected; claims to the nonelected species would still be held withdrawn from further consideration.”

This rule ensures that all potential variations within the Markush group are examined for patentability once an allowable species is identified.

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Tags: Allowable Subject Matter, markush claims, patent examination