PTAB

IPR2018-00248

Trans Ova Genetics, LC v. XY, LLC

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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 and methods for sorting animal sperm. The technology uses a fluorescent dye to stain sperm cells, which are then passed through a pulsed laser to differentiate between X and Y chromosome-bearing sperm based on differences in fluorescence, enabling sex selection.

3. Grounds for Unpatentability

Ground 1: Obviousness of Claim 42 over Evans and Piper

  • Prior Art Relied Upon: Evans (WO 01/85913) and Piper (WO 92/08120).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Evans, which shares a co-inventor with the ’116 patent, disclosed nearly every element of a flow cytometry system for sorting sperm as recited in claim 42. This included a sheath fluid port, a sample injection element, a nozzle, an oscillator, a fluorescence detector, a processing unit, a drop charge circuit, and deflection plates. The only key element Evans did not explicitly disclose was the use of a pulsed laser, instead teaching a continuous wave (CW) laser. Piper was asserted to cure this deficiency by explicitly teaching a system for flow-sorting cells that included a high-repetition pulsed laser and detailing its advantages over CW lasers.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine Evans with Piper to gain the known benefits of pulsed lasers, which Piper taught were cheaper, more reliable, and provided higher instantaneous illumination, relaxed beam focusing, and greater wavelength versatility compared to the CW lasers used in systems like Evans.
    • Expectation of Success: A POSA would have reasonably expected success in substituting the CW laser of Evans with the pulsed laser of Piper, as Piper specifically taught the effectiveness and advantages of its pulsed laser for flow cytometry applications.

Ground 2: Obviousness of Claims 42-59, 65, and 69 over Evans, Piper, and Tardif

  • Prior Art Relied Upon: Evans (WO 01/85913), Piper (WO 92/08120), and Tardif (a 1998 article in the Journal of Andrology).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon Ground 1 by adding Tardif to address the claim 42 limitation of using reduced stain concentrations (e.g., "about 60%... of maximum stain"). While Evans (via incorporation of the Johnson patent) taught using minimal stain to avoid toxicity, Tardif was argued to provide more explicit teachings. Tardif studied optimizing the evaluation of Hoechst 33342 dye-stained bull sperm and found an "optimal" concentration range of 40 to 60 µg/ml. Petitioner contended this range (equating to 67-100% of the maximum effective concentration in Tardif) rendered the claimed ranges of "about 60%" to "about 90%" obvious.
    • Motivation to Combine: Tardif provided additional motivation to use a pulsed laser, as it taught that pulsed UV illumination was less harmful to sperm than continuous exposure. A POSA would therefore be motivated to combine the teachings of Evans, Piper, and Tardif to create a sperm sorting system that was not only efficient (per Piper) but also optimized for sperm viability and staining (per Tardif).
    • Expectation of Success: A POSA would have expected success because Tardif demonstrated that its staining concentrations and pulsed illumination worked well for evaluating the same type of Hoechst-stained sperm used in the Evans system.

Ground 3: Obviousness of Claim 51 over Evans, Piper, Tardif, and Lakowicz

  • Prior Art Relied Upon: Evans (WO 01/85913), Piper (WO 92/08120), Tardif (1998 journal article), and Lakowicz (Patent 5,504,337).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground specifically targeted claim 51, which requires the pulsed laser to have a fluorescence activation wavelength of 355 nm. Petitioner argued that while Tardif disclosed a broad excitation range of 327 to 395 nm for Hoechst 33342 dye, which rendered the claimed 355 nm obvious as a point within that range, Lakowicz provided an even more explicit teaching. Lakowicz taught a flow cytometer using a pulsed laser to irradiate Hoechst 33342-stained cells and specified that the laser should operate at "325-355 nm (UV)," precisely teaching the claimed wavelength.
    • Motivation to Combine: A POSA implementing the system of Evans with a pulsed laser (per Piper and Tardif) would have looked to references like Lakowicz for specific, optimal operating parameters. Lakowicz provided the precise wavelength for exciting the specific dye used in the art, motivating its use to ensure effective fluorescence.
    • Expectation of Success: Given that Lakowicz expressly identified 355 nm as an appropriate excitation wavelength for Hoechst 33342 dye in a pulsed-laser flow cytometry context, a POSA would have had a high expectation of success.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge for claims 66 and 67 (requiring at least two nozzles) based on Evans, Piper, and Tardif in further view of Fukuda (Patent 5,173,740), which taught using two opposed nozzles to increase a flow cytometer's efficiency.

4. Key Claim Construction Positions

  • "stained sperm cells having a percentage of stain...of maximum stain": Petitioner argued this phrase was not self-explanatory. Based on the specification's examples, Petitioner proposed this 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." This construction was crucial to map prior art stain concentrations, like those in Tardif, onto the claimed ranges.
  • "detector between an X chromosome bearing sperm and a Y chromosome bearing sperm": Petitioner contended this phrase from claim 44 was nonsensical on its face, as a detector physically resides outside the sperm stream. Petitioner proposed construing it to mean the detector is "capable of distinguishing between" X and Y chromosome-bearing sperm, arguing this was the only logical interpretation of the inventors' intent.
  • "a nozzle" / "at least two nozzles": Petitioner argued that claim 42 reciting "a nozzle" and dependent claim 66 reciting that "said nozzle comprises at least two nozzles" was physically impossible. To resolve this, Petitioner proposed construing "a nozzle" in claim 42 as "at least one nozzle" to provide a proper antecedent basis for the dependent claims.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 42-59, 65-67, and 69 of the ’116 patent as unpatentable.