Peter Root focuses on complex business and commercial litigation with an emphasis on intellectual property and technology matters.

As both trial and appellate counsel, Mr. Root has handled a wide variety of civil litigation matters in federal and state court, including patent infringement and other intellectual property disputes, securities class and mass actions, shareholder derivative, unfair competition and fiduciary litigation. Mr. Root's experience also includes conducting internal investigations on behalf of management and audit committees of public companies, and representing clients in governmental and regulatory investigations. Mr. Root counsels clients on compliance, governance practices, and litigation avoidance strategies.

Prior to joining the firm, Mr. Root was an Associate General Counsel of litigation at Affymetrix, Inc., a biotech company in Silicon Valley, where he and other members of the in-house litigation team directly handled intellectual property and securities litigation matters. Earlier in his career, Mr. Root served as a Special Assistant District Attorney for the San Francisco District Attorney's Office and as a Judicial Clerk for the Honorable John T. Noonan, Jr., Circuit Judge for the United States Court of Appeals of the Ninth Circuit.

Mr. Root was a commissioned officer in the United States Navy before entering the legal profession, where he served as the Commander of a Navy SEAL platoon.


  • Google against claims of infringement of five patents relating to Digital Rights Management technology. Won complete defense verdict of non-infringement at jury trial. Case currently on appeal to the Federal Circuit. ContentGuard Holdings, Inc. v. Google, Inc. (E.D. Tex. 2015).
  • Affymetrix in a multi-party litigation in which Enzo alleged patent infringement and breach of distributorship agreements. Won summary judgment of non-infringement on patent claims, and partial summary judgment on contract claims. Achieved favorable settlement on remaining contract claims. Enzo Biochem, Inc. v. Affymetrix, Inc. (S.D.N.Y. 2010-2014).
  • Affymetrix in multi-party litigation against claims of patent infringement. Achieved favorable settlement. Enzo Life Sciences, Inc. v. Affymetrix, Inc. (D. Del. 2012-2015).
  • Affymetrix in patent infringement suit brought by MIT and its licensee, E8. Successfully moved to dismiss E8 on ground that it lacks standing to sue as "bare licensee." Following favorable claim construction ruling, plaintiffs stipulated to final judgment of non-infringement. Argued appeal at Federal Circuit and won affirmance of the judgment. E8 Pharmaceuticals LLC and Massachusetts Institute of Technology v. Affymetrix, Inc. (D. Mass/Fed. Cir. 2008-2013).
  • Sequenom in consolidated declaratory judgment and patent infringement cases involving claims by and against Sequenom for patent infringement. Case with Illumina settled. Cases against Ariosa and Natera concluded after Supreme Court denied petition for certiorari of lower courts' invalidation of Sequenom patent. Ariosa/Natera/Illumina v. Sequenom, Inc. (N.D. Cal. 2014).
  • Sequenom in litigation arising from a dispute regarding a patent licensing agreement. Filed Sequenom complaint for declaratory judgment on October 11, 2011. On same day, Life Tech filed complaint against Sequenom for declaratory judgment, breach of the licensing agreement, and unfair competition under California's Unfair Competition Law. Life Tech dismissed breach of contract claims and case settled. Sequenom v. Life Technologies Corp. and related case (San Diego Superior Court, 2011-2012).
  • OG International, a small video game company, in a declaratory judgment action against Ubisoft, the dominant player in the dance video game industry. Ubisoft counterclaimed for copyright and trade dress infringement, and unfair competition under California's Unfair Competition Law. Successfully defeated Ubisoft's motion for TRO and preliminary injunction, which sought to prevent the commercial launch of OG's allegedly infringing dance video game. Achieved walk-away settlement. OG International Ltd. v. Ubisoft, Inc. (N.D. Cal., 2011-2013).
  • Rolls-Royce in ITC investigation initiated by UTC's complaint for infringement of a patent relating to jet engine fan blade design. Case settled as part of a global settlement between the parties. United Technologies Corp. v. Rolls-Royce plc (ITC, 2010-2011).


Managing Intellectual Property
IP Star (2014-2016)
The Legal 500 US
Intellectual Property - Patent Litigation - Full Coverage (2015)
Who’s Who Legal
Life Sciences - Patent Litigation (2013, 2014 and 2016)


  • JD, University of California, Berkeley School of Law, 1989, Order of the Coif
  • BA, University of Pennsylvania, 1977, cum laude
  • California
  • California Supreme Judicial Court
  • US Court of Appeals for the Ninth Circuit
  • US District Court, Central District of California
  • US District Court, Southern District of California
  • US Tax Court
Government and Military Service
  • Navy SEAL Commander, US Navy

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