Is an actual reduction to practice required before filing a patent application for biological material?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

No, an actual reduction to practice is not a prerequisite for filing a patent application, even for biological materials. The MPEP 2406.02 clearly states:

“[T]here is no requirement in the patent law that an actual reduction to practice occur as a condition precedent to filing a patent application.”

This means that inventors can file patent applications for biological inventions based on constructive reduction to practice, which involves providing a detailed description that would enable a person skilled in the art to make and use the invention without undue experimentation.