What is a Sequence Identifier (SEQ ID NO) and how is it used in patent applications?
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.
A Sequence Identifier (SEQ ID NO) is a unique number assigned to each disclosed nucleic acid and/or amino acid sequence in a patent application. According to MPEP 2422.01:
“37 CFR 1.821(d) and 37 CFR 1.823(a)(5) require that each disclosed nucleic acid and/or amino acid sequence in the application appear separately in the “Sequence Listing”, with each sequence further being assigned a sequence identifier, referred to as “SEQ ID NO:” or the like.“
Key points about Sequence Identifiers:
- They must begin with 1 and increase sequentially by integers.
- Each sequence must have a different number for identification.
- Sequences should be presented in numerical order in the “Sequence Listing” where practical.
- When discussing a sequence in the description or claims, a reference to its SEQ ID NO is required at all occurrences.
- SEQ ID NOs can be used to discuss or claim parts of a sequence (e.g., “residues 14 to 243 of SEQ ID NO:23”).
The use of SEQ ID NOs provides a shorthand way for applicants to discuss and claim their inventions without restricting how an invention can be claimed.