Challenge
The application involved magnetic transfection of maize pollen. The USPTO initially treated the claims as narrative, indefinite, and inconsistent with U.S. method-claim practice, and rejected the claims as obvious over Zhang's cotton-pollen magnetofection work in view of Yang's low-temperature pollen treatment. After final rejection, ZYL used an RCE, claim reconstruction, specification and drawing corrections, and a new Rule 1.132 affidavit to reset the case.
The technical challenge was to prevent the invention from being reduced to “magnetofection at low temperature.” The winning theory focused the case on a maize-specific two-stage sequence: aperture-opening pretreatment in a defined transformation solution before MNP-DNA exposure, followed by low-temperature magnetic transfection.
Professional Defense
- The claims were rewritten into conventional U.S. method-claim form, with a more closed step sequence that made clear the aperture-opening pretreatment is completed before the MNP-DNA complex is added.
- The response eliminated lingering Section 112(b) problems by canceling disputed claims, removing relative or unclear terms, standardizing MNP terminology, and correcting drawing and specification issues.
- Against the Zhang/Yang combination, the response showed that Zhang describes a cotton single-step magnetofection workflow, while Yang addresses low temperature and aeration in a different pollen-treatment context. Neither reference teaches the claimed maize-specific two-stage pretreatment/transfection protocol.
- The response used Vejlupkova's independent report of failed attempts to apply Zhang-style magnetofection to monocot species, including maize, to attack reasonable expectation of success.
- The new Rule 1.132 affidavit tied the claim amendments to concrete data. The examiner's reasons for allowance recognized that aperture-opening pretreatment of maize pollen at 8°C and room temperature produced opening rates of about 40.35-50.99% and 52.82-61.61%, compared with about 3% without pretreatment.
Result
The USPTO issued a Notice of Allowance on June 9, 2026. The examiner withdrew the Section 112(b) and Section 103 rejections in light of the March 9, 2026 amendments and affidavit, and specifically recognized that the prior art did not disclose magnetic transfection of maize pollen with the claimed aperture-opening pretreatment. The case highlights ZYL's ability to combine U.S. claim rewriting, biotechnology evidence, and nonobviousness argument in a complex OA response.