Administrative Instructions under the Patent Cooperation Treaty
Annex C, Appendix 2
Nucleotide and Amino Acid Symbols and Feature Table
Table 1: List of Nucleotides
| Symbol | Meaning | Origin of designation |
|---|---|---|
| a | a | adenine |
| g | g | guanine |
| c | c | cytosine |
| t | t | thymine |
| u | u | uracil |
| r | g or a | purine |
| y | t/u or c | pyrimidine |
| m | a or c | amino |
| k |
g or t/u
|
keto |
| s | g or c | strong interactions 3H-bonds |
| w | a or t/u | weak interactions 2H-bonds |
| b | g or c or t/u |
not a |
| d
|
a or g or t/u |
not c |
| h | a or c or t/u |
not g |
| v | a or g or c |
not t, not u |
| n | a or g or c or t/u, unknown, or other |
any |