When to use ST.25 or ST.26 Format
KIPO has provided the following guidance on whether a sequence listing must comply with ST.25 or ST.26 format:
1) For an application having a “filing date” on or after July 1, 2022, any sequence listing must comply with ST.26 format, even if the application has a priority date on or before June 30, 2022. If an application is filed on or before June 30, 2022, the previous ST.25 standard applies.
2) For a PCT application and its national phase application having an “international filing date” on or after July 1, 2022, any sequence listing must comply with ST.26 format. If the international filing date is on or before June 30, 2022, it is not required to comply with the ST.26 standard upon entry into the Korean national phase on or after July 1, 2022, and the previous ST.25 standard applies.
3) For a divisional, converted, or separate application, or an application by a legitimate right-holder, whose “original” application or corresponding application by an illegitimate right-holder has a filing date on or after July 1, 2022, any sequence listing must comply with ST.26 format. Thus, for example, any sequence listing in a divisional application having a filing date on or after July 1, 2022, must comply with ST.25 format if the original application has a filing date on or before June 30, 2022.
Unlike other jurisdictions such as the US, Europe, and Japan, it is not mandatory to convert the original ST.25 sequence listing into ST.26 format for “divisional” applications in Korea.
Key changes under ST.26 standard
The big shift is that the ST.26 standard requires submission of a sequence listing in electronic “XML” format, instead of the previous TXT format.
Contrast to ST.25, ST.26 requires inclusion of i) D-amino acids, ii) linear portions of branched sequences, and iii) nucleotide analogues in sequence listing, if an application describes such sequences.
For annotation of sequences, not only “feature keys” but also “qualifiers” are required.
Further, ST.26 prohibits inclusion of sequences shorter than 10 specifically defined nucleotides or shorter than four specifically defined amino acids, which was allowed under ST.25. For such short sequences, it is recommended that the sequence listing include the corresponding sequence identification numbers only (i.e., an “intentionally skipped sequence”, also known as an empty sequence), while describing the details in the specification or drawings.
Remarks
If an application fails to comply with ST.26 (e.g., submission of a non-XML format sequence or an XML format sequence which is not compliant with ST.26), it is possible to replace it with an ST.26- compliant sequence listing, voluntarily or in response to an office action from KIPO. However, as discussed above, the ST.26 standard requires more information than ST.25. As such, there may be a risk of a new matter issue arising from submission of a converted ST.26 version, unless the details of the sequence are identified from the originally filed specification, drawings, or electronic sequence listing file. Thus, it is recommended that special care be taken to prepare and file a proper ST.26-compliant sequence listing.
Our thanks to Min SON, Ph.D., Patent Attorney for this article which was first published in the HANOL 2022/23 newsletter.