PTAB

IPR2018-00248

Trans Ova Genetics LC v. XY LLC

Log In
Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Apparatus, methods and processes for sorting particles and for providing sex-sorted animal sperm
  • Brief Description: The ’116 patent discloses a flow cytometry system for sorting animal sperm cells based on sex. The system involves staining sperm with a fluorescent dye, introducing them into a fluid stream, and passing them through a pulsed laser to excite the dye, allowing differentiation between X and Y chromosome-bearing sperm based on fluorescence levels for subsequent electrostatic sorting.

3. Grounds for Unpatentability

Ground 1: Claims 42-59, 65, and 69 are obvious over Evans in view of Piper and Tardif

  • Prior Art Relied Upon: Evans (WO 01/85913), Piper (WO 92/08120), and Tardif (a 1998 journal article).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Evans, which shares an inventor with the ’116 patent, discloses a nearly identical flow cytometry system for sorting sperm stained with Hoechst 33342 dye. Evans taught every major component of independent claim 42, including a sheath fluid port, sample injector, nozzle, oscillator, beam splitter, fluorescence detector, processing unit, drop charge circuit, and collection system. The primary elements not explicitly disclosed in Evans were the use of a "pulsed laser" and the specific claimed percentages of stain. Petitioner asserted that Tardif taught an optimal staining concentration range for Hoechst dye on bull sperm (40-60 µg/ml) that renders the claimed range of "about 60-90% of maximum stain" obvious, as the disclosed range overlaps with and suggests the claimed values.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Evans with Piper because Piper explicitly taught the numerous advantages of using a pulsed laser over a continuous wave (CW) laser in flow cytometry systems. These advantages included lower cost, increased performance, higher instantaneous illumination, and greater wavelength versatility. Further, a POSITA would be motivated to incorporate Tardif’s teachings to optimize the staining process and to minimize harm to sperm cells from UV exposure, as Tardif explained that a pulsed radiation source reduces harmful exposure time compared to a continuous source.
    • Expectation of Success: A POSITA would have a high expectation of success because Piper taught that its pulsed laser was particularly effective for flow cytometry applications like that of Evans. Similarly, Tardif’s teachings on staining and pulsed illumination were directly related to evaluating Hoechst dye-stained sperm, making the successful integration of its methods into the Evans system predictable.

Ground 2: Claim 51 is obvious over Evans in view of Piper, Tardif, and Lakowicz

  • Prior Art Relied Upon: Evans (WO 01/85913), Piper (WO 92/08120), Tardif (a 1998 journal article), and Lakowicz (Patent 5,504,337).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the combination of Evans, Piper, and Tardif to specifically address the limitation in claim 51 requiring a pulsed laser with a "fluorescence activation wavelength of 355 nm." While Tardif taught a broad excitation range (327-395 nm) for Hoechst dye that included 355 nm, Lakowicz provided a more explicit teaching. Lakowicz disclosed a flow cytometer using a pulsed laser to irradiate cells stained with Hoechst 33342 and expressly taught that the laser should be operated at "325-355 nm (UV)," identifying it as the dye's excitation/absorption wavelength.
    • Motivation to Combine: A POSITA, having already decided to implement a pulsed laser in the Evans system for reasons taught by Piper and Tardif, would look to prior art like Lakowicz for specific, optimal operating parameters. Lakowicz’s precise disclosure of the 325-355 nm range for exciting the exact dye used in Evans provided a clear motivation to select a laser operating at 355 nm to ensure efficient fluorescence.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because Lakowicz precisely taught that the 355 nm wavelength was appropriate for exciting Hoechst dye-stained DNA, ensuring the modification would function as intended within the established Evans/Piper/Tardif framework.

Additional Grounds: Petitioner asserted an additional obviousness challenge for claims 66-67 based on the combination of Evans, Piper, and Tardif in further view of Fukuda (Patent 5,173,740). Fukuda was cited for its teaching of a flow cytometer with at least two nozzles to increase efficiency, which Petitioner argued would have motivated a POSITA to modify the Evans system to achieve higher throughput.

4. Key Claim Construction Positions

  • "stained sperm cells having a percentage of stain as compared to a standard control... of maximum stain" (claim 42 et al.): Petitioner argued this phrase should be construed to mean "sperm cells stained with about 60%, 70%, 80%, or 90% of the highest concentration of dye shown to be effective at staining the sperm in any particular experiment (or set of experiments)." This construction was based on the patent’s examples, where "standard concentration" was equated with the "100% level of stain (control)."
  • "a nozzle" (claim 42) / "said nozzle comprises at least two nozzles" (claim 66): Petitioner asserted that to resolve a nonsensical limitation and lack of antecedent basis, the term "a nozzle" in independent claim 42 should be construed as "at least one nozzle." This would provide proper antecedent basis for dependent claim 66, which requires the system to comprise "at least two nozzles."

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 42-59, 65-67, and 69 of Patent 7,723,116 as unpatentable.