Beckman Coulter Inc v. Cytek Biosciences Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Beckman Coulter, Inc. (Delaware)
  • Defendant: Cytek Biosciences, Inc. (Delaware)
  • Plaintiff's Counsel: Richards, Layton & Finger P.A.; Wilmer Cutler Pickering Hale and Dorr LLP
• Case Identification: 1:24-cv-00945, D. Del., 01/09/2025
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because the Defendant, Cytek, is a Delaware corporation and, on information and belief, conducts business in the state.
• Core Dispute: Plaintiff alleges that Defendant's flow cytometer and cell sorter products infringe four U.S. patents related to optical subsystems and wavelength division multiplexing technology.
• Technical Context: The technology at issue involves optical systems within flow cytometers, which are instruments used in biomedical research and diagnostics to analyze the physical and chemical characteristics of microscopic particles, such as cells.
• Key Procedural History: The complaint notes that the parties are direct competitors and refers to a counterclaim filed by Cytek in related proceedings, suggesting a contentious history. Plaintiff alleges multiple bases for pre-suit knowledge of the asserted patents, including Cytek's admissions of awareness of the patent family, citations in Cytek's own patents, and a pre-suit notification letter sent by Beckman Coulter.

Case Timeline

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 10,330,582 - "Flow Cytometer" (issued June 25, 2019)

The Invention Explained

• Problem Addressed: The patent background describes the need for a simple and reliable optical system for flow cytometers, particularly when using laser diodes (LDs) as a light source, to deliver a focused laser beam with specific characteristics optimized for cytometric applications '582 Patent, col. 2:1-7
• The Patented Solution: The invention is an optical subsystem that manages the light path from a source to a detector '582 Patent, abstract It uses a collimating element to create a collimated beam, and then an "optical relay element" that includes a curved mirror to reflect that beam and produce an image, which is ultimately focused by another optical element onto a semiconductor detector '582 Patent, abstract '582 Patent, col. 4:35-54 This architecture is designed to extend the collimated light path, enabling the use of certain light-separating techniques '582 Patent, col. 4:50-57
• Technical Importance: This design aims to improve the quality and management of the light signal within a flow cytometer, which can enhance detection sensitivity and support more complex, multi-parameter analyses.

Key Claims at a Glance

• The complaint asserts at least independent claim 1 Compl. ¶29
• Claim 1 of the '582 Patent breaks down into the following essential elements:
  • An optical subsystem for a flow cytometer, comprising:
  • a collimating optical element arranged to receive light from a light source and configured to project a collimated beam;
  • an optical relay element arranged to receive at least a portion of the collimated beam, the optical relay element comprising a curved mirror configured to reflect the portion of the collimated beam to produce a first image;
  • a first focusing optical element arranged to receive at least a portion of the collimated beam reflected by the optical relay element; and
  • a first semiconductor detector,
  • wherein the first focusing optical element is configured to focus the portion of the collimated beam received from the optical relay element onto the first semiconductor detector.
• The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 11,703,443 - "Flow Cytometer" (issued July 18, 2023)

The Invention Explained

• Problem Addressed: The patent, which shares a specification with the '582 Patent, addresses the need for a Wavelength Division Multiplexing (WDM) system to separate a light beam into multiple colored bands for detection, particularly a system that is compatible with low-noise semiconductor detectors and is reconfigurable '443 Patent, col. 2:30-36
• The Patented Solution: The invention is a specific architecture for a WDM. It comprises a set of filters, at least one curved mirror, and a set of detectors '443 Patent, abstract The mirror is configured to receive light portions from the filters and reflect them back to the filters, creating a folded optical path that allows for the separation of different wavelengths of light to be routed to corresponding detectors '443 Patent, col. 17:1-17
• Technical Importance: This WDM architecture enables the simultaneous detection of multiple distinct light signals (e.g., from different fluorescent markers on a cell) within a single, compact optical module.

Key Claims at a Glance

• The complaint asserts at least independent claim 1 Compl. ¶37
• Claim 1 of the '443 Patent breaks down into the following essential elements:
  • A wavelength division multiplexer (WDM) for a flow cytometer comprising:
  • a set of filters, each configured to pass a corresponding portion of multiple portions of light;
  • at least one mirror including at least one curved mirror, configured to:
    • receive one or more portions of the light from the set of filters; and
    • reflect the one or more portions of the light to the set of filters; and
  • a set of detectors, each corresponding to a filter and configured to receive a portion of the light that passed through the filter.
• The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 12,174,106 - "Flow Cytometer" (issued December 24, 2024)

• Technology Synopsis: This patent describes a flow cytometer with a specific optical collection and separation system. A collecting optical element focuses fluorescent light, which is then passed to a WDM containing a separate collimating element, a first curved mirror, and a first dichroic filter to separate the light into a first color band (which passes to a detector) and a second color band (which is reflected away) '106 Patent, claim 1
• Asserted Claims: At least independent claim 1 Compl. ¶45
• Accused Features: The accused products' optical subsystems, which allegedly use a collecting optical element, a WDM with a collimating element, a curved mirror, and a dichroic filter to separate and detect different color bands of fluorescent light Compl. ¶¶46-47

U.S. Patent No. 12,174,107 - "Flow Cytometer" (issued December 24, 2024)

• Technology Synopsis: This patent claims a flow cytometer comprising an optical fiber and a WDM. The WDM itself comprises an array of mirrors, an array of filters, and an array of avalanche photodiodes (APDs). The mirrors are configured to receive light reflected by one filter and reflect it to another filter, creating a path for wavelength separation '107 Patent, claim 1
• Asserted Claims: At least independent claim 1 Compl. ¶53
• Accused Features: The accused products' WDM, which allegedly receives light and uses an array of mirrors, filters, and detectors to separate and detect different wavelengths Compl. ¶¶54-55

III. The Accused Instrumentality

Product Identification

• The accused products are the Cytek Aurora flow cytometers, Cytek Aurora CS cell sorters, Cytek Northern Lights, and Cytek Northern Lights-CLC products (collectively, the "Infringing Products") Compl. ¶¶14-15

Functionality and Market Context

• The complaint describes these products as flow cytometers and cell sorters used for biological analysis Compl. ¶14 A central feature identified in the complaint is the products' use of "optical filter-based coarse wavelength division multiplexing (CWDM) demultiplexer arrays" to collect and separate emitted light for detection Compl. ¶14 Compl. ¶18 Compl. ¶32 The complaint provides a diagram from a Cytek marketing document illustrating the accused "Proprietary high sensitivity Coarse Wavelength Division Multiplexing (CWDM) semiconductor detector arrays" Compl. ¶8 Plaintiff alleges that these products are in direct competition with its own CytoFLEX line of flow cytometers and cell sorters Compl. ¶23

IV. Analysis of Infringement Allegations

10,330,582 Infringement Allegations

• Identified Points of Contention:
  • Scope Questions: A potential point of dispute may be whether the components inside Cytek's "CWDM demultiplexer arrays" meet the structural and functional definition of an "optical relay element" as claimed. The analysis may turn on whether the accused mirrors "produce a first image" in the specific manner required by the claim.
  • Technical Questions: A factual question for the court will be to determine the precise light path and function of each component within the accused products' optical systems and compare it to the architecture defined in Claim 1.

11,703,443 Infringement Allegations

• Identified Points of Contention:
  • Scope Questions: The infringement analysis will likely focus on the specific functional requirements of the mirror element. A question for construction may be what is required for a mirror to "receive one or more portions of the light from the set of filters" and "reflect the one or more portions of the light to the set of filters."
  • Technical Questions: The case may raise the factual question of whether the light path within the accused CWDM operates in the specific reflective loop (from filters, to mirror, back to filters) required by the claim, or if it uses a different technical method for wavelength separation.

V. Key Claim Terms for Construction

• The Term: "optical relay element" '582 Patent, claim 1

• Context and Importance: This term is central to the claimed architecture of the '582 Patent. Its construction will be critical because the infringement analysis depends on whether a component within the accused Cytek products, likely a mirror within its CWDM, performs the functions of this element, including producing a "first image." Practitioners may focus on this term to determine if the claim requires a specific imaging function beyond simple reflection.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification describes the second optical element (the relay) as one that "relays the first optical element with unit magnification down the optical path," which "effectively doubles the collimated path length" '582 Patent, col. 4:45-51 This functional description could support an interpretation that covers any curved mirror arrangement achieving that purpose.
  • Evidence for a Narrower Interpretation: Claim 1 itself requires the relay element's curved mirror be "configured to... produce a first image." Embodiments like Figure 25 show a specific concave mirror (907) creating an image near a subsequent focusing lens (908), which may suggest a more limited structural and functional scope.

• The Term: "configured to: receive one or more portions of the light from the set of filters; and reflect the one or more portions of the light to the set of filters" '443 Patent, claim 1

• Context and Importance: This functional language defines the core operation of the mirror within the claimed WDM of the '443 Patent. The dispute will likely center on whether the mirrors in Cytek's products perform this specific two-step action of receiving from and reflecting back to the same set of filters. Practitioners may focus on this phrase as it dictates a specific, folded light path that may or may not be present in the accused devices.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent's general description of a WDM is to "separate a light beam into multiple colored bands" '443 Patent, col. 2:30-32 This could support a reading where any mirror system contributing to this overall function meets the claim.
  • Evidence for a Narrower Interpretation: The claim language recites a specific sequence: light goes to the filters, then to the mirror, then back to the filters. The embodiment in Figure 25 shows light passing through a first dichroic filter (903), reflecting off a concave mirror (907), and then encountering a second dichroic filter (909), which could be argued to be part of the same "set." This specific path may support a narrower construction that the accused products might not meet.

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement for all asserted patents. Inducement is based on allegations that Cytek provides customers with user guides and instructions (Exhibits 5 and 6) that encourage use of the products in an infringing manner Compl. ¶32 Compl. ¶40 Compl. ¶48 Compl. ¶56 Contributory infringement is based on allegations that the accused products are a material component of the patented combinations and are not staple articles of commerce Compl. ¶33 Compl. ¶41 Compl. ¶49 Compl. ¶57
• Willful Infringement: The complaint alleges willful infringement based on both pre-suit and post-suit knowledge. Pre-suit knowledge is alleged based on Cytek being a direct competitor that monitors Beckman Coulter's patent portfolio Compl. ¶19, Cytek's own patents citing the asserted patent family Compl. ¶19, Cytek's alleged admission of becoming aware of the '582 Patent on July 31, 2020 Compl. ¶20, Beckman Coulter's virtual marking of its products Compl. ¶22, and a pre-suit notice letter sent on June 14, 2024 Compl. ¶24 Post-suit knowledge is based on the filing of the original complaint on August 14, 2024 Compl. ¶25

VII. Analyst's Conclusion: Key Questions for the Case

• A core issue will be one of claim construction: how broadly will the court interpret the functional requirements of key elements, such as the "optical relay element" in the '582 patent and the specific light path (from filters, to mirror, to filters) recited for the WDM in the '443 patent? The outcome of these definitional disputes may be dispositive of infringement.
• A central evidentiary question will be one of technical operation: does the accused "CWDM demultiplexer array" in Cytek's products function in the specific manner claimed in the patents? The case will likely require expert testimony to dissect the precise light path and function of the components in the accused devices for comparison against the claim language.
• A further key question, should infringement be found, will relate to willfulness: do the extensive allegations in the complaint-including alleged admissions of awareness and competitive monitoring-establish that Cytek acted with objective recklessness despite a high likelihood of infringement, which could expose the defendant to enhanced damages?