What are the standard single-letter codes for modified and unusual nucleotides in WIPO ST.25?
What are the standard single-letter codes for modified and unusual nucleotides in WIPO ST.25?
WIPO ST.25 provides standard single-letter codes for modified and unusual nucleotides in sequence listings. According to MPEP 2423:
“The nucleotides listed in Appendix 2, Table 2, are the only permitted nucleotides. Where a sequence includes “other” nucleotides, they must be represented as “n” and further described in a feature table, as provided by Appendix 2, Section 7.”
Some key codes include:
- n – any nucleotide (a, c, g, or t/u)
- r – purine (a or g)
- y – pyrimidine (c, t, or u)
- m – a or c
- k – g or t/u
- s – c or g
- w – a or t/u
For any modified or unusual nucleotides not covered by these codes, use “n” and provide additional details in the feature table.
To learn more:
Topics:
MPEP 2400 - Biotechnology,
MPEP 2423 - Symbols And Format To Be Used For Nucleotide And/Or Amino Acid Sequence Data For Wipo St.25,
Patent Law,
Patent Procedure