Why does it matter that biological sequences may be claimed in patents and patent applications?
A U.S. Patent gives a patentee the right to exclude others from using the patented technology in the U.S. The patentee may allow others to use the technology only upon payment of license fees or royalties, or may not allow its use at all. U.S. laws also give the patentee the right to prevent import of implementations from other countries that use the technology patented in the U.S., even if it is not patented in the country of origin.
Isolated DNA sequences claimed under “composition of matter” claims in a U.S. patent are like any other patented technology in this respect. If used in a way that is covered by the claims of a patent that is in force, the user may be subject to being stopped by injunction or being required to pay royalties.
Many US patents on DNA and amino acid sequences, giving the right to exclude use in the US or in implementations that will be imported into the US, are owned by private companies, or by public sector institutions that have often exclusively licensed the rights to private companies.
Sequences identified here are in published U.S. patent applications. Patents over these sequences may or may not eventually or already be granted. However, potential users of any such sequence are considered to be “on notice” from the published patent application that they may be required to obtain a license in exchange for payments if a patent is granted. Under U.S. law, the patentee may be entitled to charge royalties from the date of publication. Thus, though a biological sequence might be published in a journal or Genbank, but it could be no more “public” than the copyrighted matter of a published book or a movie in theaters is “in the public domain.” If it’s in a patent application, furthermore, uncertainty about whether a patent may be granted is often enough to deter potential users and investors.