How does the USPTO determine if a negative limitation has written description support?
How does the USPTO determine if a negative limitation has written description support?
The USPTO examines negative limitations for written description support based on the guidance provided in MPEP 2173.05(i). The key factors include:
- Express disclosure in the specification
- Inherent disclosure based on what is described
- Original claims
- Drawings that show the absence of a feature
The MPEP states: “Any negative limitation or exclusionary proviso must have basis in the original disclosure.” This means that the negative limitation must be supported by the original specification, either explicitly or implicitly.
For example, if the specification describes a composition “without additive X,” a claim limitation stating “wherein the composition is free of additive X” would likely have sufficient support. However, introducing a negative limitation that was not contemplated in the original disclosure could be considered new matter and rejected under 35 U.S.C. 112(a).
To learn more:
Topics:
MPEP 2100 - Patentability,
MPEP 2173.05(I) - Negative Limitations,
Patent Law,
Patent Procedure