How does an examiner handle an allowable elected species in a Markush claim?

When an elected species in a Markush claim is found allowable over the prior art, the examiner must extend the search and examination to other species within the Markush grouping. MPEP 803.02 provides guidance on this process:

“If the elected species or group of patentably indistinct species is not anticipated by or obvious over the prior art, the examiner should extend the search and examination to a non-elected species or group of species that falls within the scope of a proper Markush grouping that includes the elected species.”

The examiner continues this process until either:

1. Prior art is found that anticipates or renders obvious a species within the proper Markush grouping, or
2. It is determined that no prior art rejection can be made for any species within the proper Markush grouping

Importantly, the examiner is not required to extend the search beyond a proper Markush grouping. The examination should also include determining whether the Markush claim meets all other requirements of patentability.

To learn more:

• allowable species
• Markush claims
• patent examination
• prior art search
• extended examination