What is the difference between ST.25 and ST.26 for Sequence Listings?

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.

The main differences between ST.25 and ST.26 for Sequence Listings, as implied in MPEP 2415.01, are:

• Format: ST.25 used a text-based format, while ST.26 requires XML format
• Application Date: ST.25 applied to applications filed before July 1, 2022, while ST.26 applies to applications filed on or after July 1, 2022
• Standardization: ST.26 provides a more standardized approach across different patent offices

The MPEP states: “For applications filed on or after July 1, 2022, all sequence listings must be submitted as an XML file named ‘SequenceListing.xml’ in accordance with the ‘Standard for the Presentation of Nucleotide and Amino Acid Sequence Listings in Patent Applications’ (hereinafter ‘ST.26 Standard’).”

This transition from ST.25 to ST.26 represents a significant change in how Sequence Listings are submitted and processed in patent applications.