Cytek Biosciences, Inc. v. Beckman Coulter, Inc.

Cytek Biosciences, Inc., a publicly traded cell analysis solutions company known for its Full Spectrum Profiling™ (FSP™) technology and instruments like the Aurora and Northern Lights™ flow cytometers, initiated a Post-Grant Review (PGR) against Beckman Coulter, Inc. Beckman Coulter, a subsidiary of Danaher Corporation, is a major American company specializing in biomedical testing, offering diagnostic systems and life science research instruments. The underlying dispute involves allegations by Beckman Coulter that Cytek's Aurora flow cytometers infringe on its "wavelength division multiplexing" optical patents.

The PGR proceeding, PGR2025-00084, challenged the validity of U.S. Patent No. 12,174,106, owned by Beckman Coulter. This patent generally pertains to optical elements within flow cytometry systems, specifically describing mechanisms for collecting and focusing fluorescent light emitted by particles illuminated by a light source. This PGR was filed with the U.S. Patent and Trademark Office's Patent Trial and Appeal Board (PTAB). The PTAB ultimately denied Cytek's petition to institute the PGR, resulting in the termination of the proceeding and leaving the claims of the '106 patent unaltered by this particular challenge.

This case is notable primarily due to its connection to ongoing district court litigation, Beckman Coulter, Inc. v. Cytek Biosciences, Inc. (C.A. No. 1:24-cv-00945-CFC) in the U.S. District Court for the District of Delaware, presided over by Chief Judge Colm F. Connolly. Cytek had indicated its intent to challenge the '106 patent and others in post-grant review based on obviousness and indefiniteness grounds (35 U.S.C. §§ 103 and/or 112) within that district court case. The denial of institution for this PGR at the PTAB strengthens Beckman Coulter's position regarding the validity of the '106 patent in the parallel infringement lawsuit, impacting the competitive landscape between these two significant players in the flow cytometry and biomedical testing industries.

Cytek Biosciences, Inc. and Beckman Coulter, Inc. are involved in both a patent infringement litigation in the U.S. District Court for the District of Delaware and parallel Post-Grant Review (PGR) proceedings at the Patent Trial and Appeal Board (PTAB).

District Court Patent Infringement Litigation: Beckman Coulter, Inc. v. Cytek Biosciences, Inc. (1:24-cv-00945, D. Del.)

Filing & Initial Pleadings:

• Complaint: On August 14, 2024, Beckman Coulter, Inc. filed a patent infringement complaint against Cytek Biosciences, Inc. in the U.S. District Court for the District of Delaware (Case No. 1:24-cv-00945). Beckman Coulter alleged willful infringement over Cytek's Aurora flow cytometers and optical patents.
• Patents Asserted: The initial complaint asserted U.S. Patent Nos. 10,330,582, 11,703,443, and 12,174,107.
• Jury Demand: Beckman Coulter demanded a jury trial.
• Counterclaims: Cytek Biosciences, Inc. filed counterclaims against Beckman Coulter, Inc. Cytek also filed its Corrected Election of Asserted Prior Art Grounds for the asserted patents on November 25, 2025.

Pre-trial Motions of Substance:

• Motion to Stay Pending PTAB Review: Cytek Biosciences filed a motion to stay the district court litigation pending an Inter Partes Review (IPR) proceeding. Chief Judge Connolly denied this motion on August 1, 2025. [cite: 7 in prior response, 9] The court noted that Cytek had filed an IPR petition for one of the three patents-in-suit but sought a stay based on its intent to challenge the remaining two patents later, which the court deemed insufficient grounds for a stay. [cite: 7 in prior response]
• Summary Judgment Motions: Both parties have filed multiple motions for summary judgment. Beckman Coulter filed motions addressing Cytek's "Reverse Doctrine of Equivalents" defense, failure to mark defense, and anticipation arguments related to the '443 patent. Cytek Biosciences filed motions seeking summary judgment of non-infringement for claims of the '582, '443, and '107 patents, and summary judgment of invalidity for claims of the '443 and '107 patents. These motions, along with various Daubert motions to preclude expert testimony, were filed, with answering briefs due by March 27, 2026.
• Discovery Disputes: The parties have engaged in numerous discovery disputes resolved by the magistrate judge. [cite: 7 in prior response] Notably, Cytek served third-party subpoenas on Danaher Corporation, Beckman Coulter's parent company. Danaher moved to quash these subpoenas, resulting in a partial grant and partial denial by the court. The document subpoena was quashed, but a limited deposition concerning Danaher's 2018 valuation of Cytek was permitted. [cite: 3 in prior response] Beckman Coulter also objected to an order to narrow its asserted claims due to alleged discovery deficiencies by Cytek. [cite: 5 in prior response]

Claim Construction (Markman) Outcomes:

• Claim Construction Briefing: The parties completed claim construction briefing. [cite: 7 in prior response]
• Markman Hearing: A Markman hearing was scheduled for August 21, 2025. [cite: 7 in prior response] A Markman hearing transcript from August 21, 2025, and another from September 17, 2025, are referenced in court documents. Cytek Biosciences filed its proposed claim constructions on May 14, 2025, which included terms from U.S. Patent No. 12,174,106, in addition to the asserted patents. [cite: 6 in prior response]

Discovery Milestones with Strategic Significance:

• Fact discovery was scheduled to be substantially completed by August 22, 2025, and fully completed by October 8, 2025. [cite: 5 in prior response, 7 in prior response] Beckman Coulter raised concerns about Cytek's compliance with discovery obligations, noting less than 45% of Cytek's production was submitted by the substantial completion deadline. [cite: 5 in prior response]

Trial Events, Verdict, and Post-Trial Motions:

• Trial Date: A jury trial is scheduled for August 17, 2026.

Final Disposition or Present Posture:

• The litigation remains active and is proceeding towards trial in August 2026.

Parallel PTAB IPR/PGR Proceedings

PGR2025-00084 (U.S. Patent No. 12,174,106):

• Filing: Cytek Biosciences, Inc. filed a Post-Grant Review (PGR) petition (PGR2025-00084) challenging the validity of U.S. Patent No. 12,174,106 on September 14, 2025.
• Institution Decision and Outcome: The Patent Trial and Appeal Board (PTAB) denied the petition to institute the PGR. This denial terminated the proceeding, leaving the claims of the '106 patent unaltered by this specific PTAB challenge, as stated in the existing case summary.

Other PTAB Proceedings:

• IPR2025-01319: Cytek Biosciences, Inc. also filed an Inter Partes Review (IPR) petition (IPR2025-01319) against Beckman Coulter, Inc. on July 16, 2025. This IPR is related to the ongoing district court litigation, as evidenced by citations to district court documents within its filings.

Effect on the Litigation:

• The denial of institution in PGR2025-00084 means that Cytek Biosciences cannot rely on a PTAB invalidity finding for U.S. Patent No. 12,174,106 in the district court case. Any challenges to the validity of the '106 patent in the district court would need to proceed through the court's own validity determination process. The fact that the '106 patent was included in Cytek's proposed claim constructions in the district court case indicates its relevance, even if not explicitly listed as an asserted patent in initial search snippets. The existence of multiple parallel PTAB proceedings (PGR2025-00084 and IPR2025-01319) indicates Cytek's multi-pronged approach to challenge Beckman Coulter's patents.

Here is the counsel of record representing Cytek Biosciences, Inc. (Petitioner) in PGR2025-00084:

• Dustin M. Knight

  • Role: Associate
  • Firm: Cooley LLP, Washington, DC
  • Experience Note: Skilled intellectual property litigator with experience in federal court and PTAB, particularly in medical device and tech patent cases, including successfully defending against IPR challenges and securing jury trial victories for clients.

• Reuben Chen

  • Role: Partner
  • Firm: Cooley LLP, Palo Alto, CA
  • Experience Note: Leads intellectual property litigation with a focus on patent and trade secret cases across various technologies, with a proven record in US district courts, Federal Circuit, ITC, and USPTO proceedings.

• Adam Pivovar

  • Role: Partner
  • Firm: Cooley LLP, Washington, DC
  • Experience Note: Focuses on complex patent and technology disputes, with substantial trial experience in fields including medical products, biotechnology, and pharmaceuticals, and has secured decisive victories at the ITC.

• Dr. HanByul Chang

  • Role: Associate
  • Firm: Cooley LLP, Palo Alto, CA
  • Experience Note: Specializes in patent infringement, Hatch-Waxman, BPCIA, and trade secret cases across industries like pharmaceutical, software, chemical, and medical devices.

Beckman Coulter, Inc., the patent owner in PGR2025-00084, is represented by counsel from Wilmer Cutler Pickering Hale and Dorr LLP (WilmerHale).

The counsel of record for Beckman Coulter, Inc. includes:

• Laura Macro - Lead Counsel
  • Firm: Wilmer Cutler Pickering Hale and Dorr LLP, New York, NY (based on phone number)
  • Experience Note: Laura Macro (Reg No. 80,908) was designated as lead counsel in this PGR proceeding after the previous lead counsel withdrew. Her practice focuses on intellectual property litigation, particularly in the biotechnology and pharmaceutical sectors.
• Akkad Moussa - Backup Counsel
  • Firm: Wilmer Cutler Pickering Hale and Dorr LLP, Washington, DC (based on phone number)
  • Experience Note: Akkad Moussa (Reg No. 77,078) is a registered patent attorney involved in intellectual property litigation.
• Omar Khan - Backup Counsel
  • Firm: Wilmer Cutler Pickering Hale and Dorr LLP, New York, NY (pro hac vice to be filed, based on phone number)
  • Experience Note: Omar Khan is involved in patent litigation and PTAB proceedings, and appears as counsel in related patent infringement matters for Beckman Coulter.
• Jeffrey A. Dennhardt - Backup Counsel
  • Firm: Wilmer Cutler Pickering Hale and Dorr LLP, New York, NY (pro hac vice to be filed, based on phone number)
  • Experience Note: Jeffrey Dennhardt is listed as backup counsel for Beckman Coulter.
• Jennifer L. Graber - Backup Counsel
  • Firm: Wilmer Cutler Pickering Hale and Dorr LLP, New York, NY (based on firm listing for Omar Khan and Jeffrey Dennhardt, and previous communication involving attorneys from this office)
  • Experience Note: Jennifer L. Graber (Reg. No. 80,059) is also involved in related patent disputes for Beckman Coulter.
• Patrick E. Nyman - Backup Counsel
  • Firm: Wilmer Cutler Pickering Hale and Dorr LLP, Washington, DC (based on phone number)
  • Experience Note: Patrick Nyman (Reg. No. 76,123) serves as backup counsel in this proceeding.

Previously, Alexis R. Cohen was lead counsel but withdrew from representation as of January 26, 2026, because she is no longer affiliated with WilmerHale.