How does the Patent Cooperation Treaty (PCT) affect the examination of national stage applications?

The Patent Cooperation Treaty (PCT) significantly affects the examination of national stage applications in the following ways:

• It introduces the concept of unity of invention, which is different from the independent and distinct analysis used for non-PCT applications.
• National stage applications submitted under 35 U.S.C. 371 are subject to unity of invention analysis.
• Examiners must follow specific guidelines outlined in MPEP Chapter 1800 when dealing with PCT applications.

MPEP 823 states: “The analysis used to determine whether the Office may require restriction differs in national stage applications submitted under 35 U.S.C. 371 (unity of invention analysis) as compared to national applications filed under 35 U.S.C. 111(a) (independent and distinct analysis).”

However, it’s important to note that other substantive and procedural matters, such as double patenting rejections, election and reply by applicant, and rejoinder of nonelected inventions, generally apply to national stage applications as well.

To learn more:

• PCT
• Patent Cooperation Treaty
• National Stage Applications
• Unity of Invention
• Patent Examination