PTAB challenges

Analysis of PTAB Proceedings for U.S. Patent No. 12,174,106

To: Defendant in Litigation
From: Senior PTAB Analyst
Date: 2026-05-13
Subject: Analysis of AIA Trial Proceedings for U.S. Patent No. 12,174,106

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Proceedings Overview

A single Post-Grant Review (PGR) has been filed against U.S. Patent No. 12,174,106. The Patent Trial and Appeal Board (PTAB) denied institution of this proceeding, leaving all claims of the patent intact. This outcome is favorable to the patent owner, Beckman Coulter, and suggests that overcoming the patent's validity based on the grounds presented in the petition will be challenging, though other invalidity arguments remain available.

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PGR2025-00084 — Cytek Biosciences, Inc. v. Beckman Coulter Inc.

• Type: Post-Grant Review
• Filed: 2025-09-15
• Status: Institution Denied (as of 2026-04-17). This means the PTAB determined the petition did not meet the required threshold to start a trial.
• Judge Panel: Public records do not currently name the Administrative Patent Judges on the panel for the institution decision.
• Petition Grounds: While the full petition is not publicly available, related district court filings indicate that Cytek intended to challenge the patent's claims as invalid for failing to meet the requirements of 35 U.S.C. §§ 103 (obviousness) and/or 112 (written description/enablement).
• Institution Decision: The petition was denied on 2026-04-17. The specific reasoning for the denial is not detailed in the available public records, but the "Institution Denied - Merits" status indicates the Board found the petitioner, Cytek Biosciences, Inc., did not establish that it was more likely than not that at least one of the challenged claims was unpatentable.
• Final Written Decision: Not applicable as the trial was not instituted.
• Settlement / Termination: There is no public record of a settlement. The proceeding was terminated at the institution phase.
• Appeal: Decisions to deny institution of an AIA trial are not appealable to the Federal Circuit.
• Defensive Value: The denial of institution signifies that the specific arguments and prior art combinations raised by Cytek were deemed insufficient by the PTAB to warrant a full review. While this strengthens the patent owner's position regarding the challenged grounds, it does not preclude a defendant from raising different invalidity arguments in district court or in a future PTAB petition, subject to estoppel provisions.

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Strategic Summary

• Claim Status: All claims of U.S. Patent No. 12,174,106 remain valid and enforceable. No claims have been canceled or amended through a PTAB trial. The entire patent is UNTESTED in a completed AIA trial.
• Estoppel Landscape: The petitioner, Cytek Biosciences, Inc., and any real parties in interest are now estopped under 35 U.S.C. § 325(e)(1) from filing another PGR on the '106 patent. They are also estopped from raising in any other forum, including the parallel district court litigation (Beckman Coulter, Inc. v. Cytek Biosciences, Inc., C.A. No. 24-945-CFC (D. Del.)), any invalidity ground that they "raised or reasonably could have raised" in the PGR. For any other potential defendant, all prior art grounds remain available for a potential inter partes review (IPR) petition, provided it is filed within the one-year statutory window after being served with a complaint.
• Pattern Signals: The PGR was filed in the context of ongoing district court litigation between Beckman Coulter and Cytek. This is a common strategy for defendants to attempt to invalidate an asserted patent in a faster, specialized forum. The denial of institution, however, represents a significant setback for the petitioner-defendant, Cytek. There is evidence of contentious discovery and motions practice in the related court case, indicating a hard-fought dispute.

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Recommended Next Steps

• For a defendant facing an assertion of this patent, it is crucial to understand that the patent has survived its first validity challenge at the PTAB. The denial of institution in PGR2025-00084 means the Board was not persuaded by the petitioner's initial arguments.
• A defendant should obtain the complete file history for PGR2025-00084 from the USPTO's Patent Center portal. A thorough review of Cytek's petition and Beckman Coulter's Preliminary Response will reveal the specific invalidity theories that the Board found unpersuasive. This analysis is critical to avoid presenting similar, already-blessed arguments in court.
• Given the "Institution Denied - Merits" status, any future invalidity defense, whether in court or at the PTAB, must be based on stronger prior art or different legal arguments than those presented by Cytek.
• The absence of any successful PTAB challenges to date can be viewed as a signal of the patent's relative strength, at least against the art and arguments so far presented. Any new defendant should proceed with the understanding that a validity challenge will require novel and compelling arguments.