By Monica Heger
The US Patent and Trademark Office has ruled in a patent interference case involving Pacific Biosciences and Life Technologies, deeming all of Life Tech's involved claims and the broadest claims of both companies unpatentable, effectively ending the case unless Life Tech decides to appeal.
The dispute involves a patent held by Life Technologies and a patent application by Pacific Biosciences that are both related to single-molecule sequencing technology. The case began just over two years ago, and in 2009 PacBio was named senior party of the case due to patent priority dates that preceded Life Tech's filing by 20 months (IS 3/31/2009). Even though Life Tech had originally been named senior party, it did not dispute the USPTO's decision at the time.
The Life Tech patent, US No. 7,329,492, "Methods for real-time single molecule sequence determination," was assigned in 2008 to VisiGen Biotechnologies, which Life Tech acquired that same year. PacBio's patent application, No. 11/459,182, "A system and method for nucleic acid sequencing by polymerase synthesis," was filed in 2006 by Li-Cor Biosciences, from whom PacBio purchased sequencing-related technology in 2008.
The interference concerns both companies' methods for single-molecule sequencing, and specifically the use of tagged nucleoside triphosphates to read sequence information. While both methods describe the use of a quencher, fluorescent, or dye tag, the Life Tech method depends on the interaction of the NTP tag and the polymerase tag to detect sequence information, while in the PacBio method, the sequence information is detected when the NTP is hydrolyzed.
In its decision, the USPTO's Board of Patent Appeals and Interferences ruled all of LifeTech's claims to be unpatentable for "lack of written description support," thus making the patent interference case moot. However, two of the LifeTech claims had previously been excluded from the case, and the company will retain those under the granted patent.
PacBio's broadest claims were deemed unpatentable, also for lack of written description support. In addition, the board recommended that when the patent examiner resumes its evaluation of PacBio's patent application, it consider whether those claims are patentable in light of LifeTech's other published claims. In its decision, the board said that ruling on those claims was outside the scope of the case. Thus, there is no guarantee that the remainder of PacBio's claims will be granted patent protection.
LifeTech can challenge the decision either by requesting a re-hearing, appealing to a district court, or appealing to a federal circuit.
In a statement, PacBio's CEO Hugh Martin said that the USPTO has, "in essence, stated that these claims of the Life Technologies patent never should have been issued, and we completely agree." He further noted that the claims in the dispute, including PacBio's own claims that were deemed unpatentable by the board, are not related to PacBio's RS system.
A PacBio spokesperson clarified that the ruling would not impact development of the company's SMRT technology in any way, and said that the claims in the interference case are part of the patent portfolio acquired from Li-Cor and unrelated to the RS.
In a statement to In Sequence, Life Technologies said that it is "pleased that this administrative decision from the USPTO holds that Pacific Biosciences is not entitled to the broad single molecule sequencing claims it was seeking, and we will continue to vigorously defend and build our own patent estate in this area."
It is not clear what the impact of the USPTO's decision may be on Life Tech's single-molecule sequencing technology, which is still in development.
The so-called "Starlight" technology uses a quantum dot nanocrystal tethered to a DNA polymerase as a photon source for four-color terminally labeled nucleotides. It measures light emitted from both the Qdot and the labels in real time as bases get incorporated by the polymerase. When the correct nucleotide binds to the polymerase, the Qdot transfers some of its light to the nucleotide dye via Förster resonance energy transfer, or FRET (IS 3/2/2010).
Life Tech predecessor Invitrogen acquired VisiGen in order to gain the intellectual property surrounding the FRET-based technology and was also developing its own FRET-based sequencing approach in parallel. In its most recent descriptions of the Starlight technology, Life Tech has not acknowledged any contribution from VisiGen.
Life Tech is currently in litigation with VisiGen co-founder and former CEO Susan Hardin over alleged breach of contract and other accusations (IS 1/20/2010). That case is still pending.
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