US 11346782

I'll search for authoritative information on US 11,346,782.

Summary of US 11,346,782 (searched as of 2026-04-26)

Important scoping note: My searches for the literal string "11346782" in litigation/docket contexts returned no U.S. litigation or CAFC/Federal Circuit activity involving this patent. The non-patent hits that matched the bare number "11346782" were unrelated identifiers — a UK Companies House registration number (Pixel Bar Leeds Limited, London Gazette) and an Estonian business registry code (OÜ Vedas). Per the strict-interpretation rule I am reporting those literally rather than treating them as patent records; they are not this patent. I did not find any USPTO PTAB proceeding or court docket asserting US 11,346,782.

Bibliographic data (from the patent record)

Google Patents lists the current assignee as "Wuhan Walter Billion Biological Co Ltd." Separately, a HUST technology-transfer notice (公示〔2024〕44号, dated 2024-10-08) states HUST agreed to transfer this and two related Chinese patents to 武汉沃亿生物有限公司 for ¥1,010,000, consistent with the recorded 2025 assignment. (Search results, not a legal conclusion.)

Abstract

A tomographic imaging method including the steps of: activating fluorescence in a surface layer of a protein-marked or fluorescent-dye-marked biological tissue sample that does not emit fluorescence (or emits only specific fluorescence), to obtain an activated surface biological tissue sample; performing fluorescence excitation and imaging on that sample to acquire a fluorescence image of the surface layer; cutting off the surface layer and exposing an inactivated new surface layer; repeatedly performing the activating, imaging and cutting-off steps to repeat tomographic imaging until a two-dimensional image of each layer is acquired; and overlapping the two-dimensional images to acquire a complete three-dimensional image of the biological tissue sample.

Plain-language overview of the independent claim(s)

I was able to retrieve claim-ordered text corresponding to the granted claims (Google Patents, US11346782B2 claims section) plus the mirrored "preferably" language in the specification. The broadest independent claim recites a method comprising, in substance:

1. (Activating) Activating surface fluorescence of an "original biological tissue sample" that either (a) does not emit fluorescence, or (b) emits fluorescence only in a specific waveband — thereby producing an "activated surface biological tissue sample."
2. (Imaging) Exciting and imaging fluorescence from the activated surface layer to obtain a fluorescence image of that layer.
3. (Cutting) Cutting off the activated surface layer to expose an inactivated new surface layer, and treating the resulting sample as the "original biological tissue sample."
4. (Iterating) Repeating the activating step until the remaining original sample thickness is smaller than the surface-layer thickness.
5. (Reconstructing) Overlapping the fluorescence images of each acquired surface biological tissue sample to obtain a complete three-dimensional image of the original biological tissue sample.

Plain-language core idea: instead of optically sectioning (confocal/two-photon/light-sheet) or physically slicing and separately staining, the sample is chemically or photochemically "switched", and the fluorescence is only "turned on" in a thin surface layer (chemical permeation depth or short-wavelength activation depth). The activated surface is imaged with a simple wide-field optical system, then microtomed off (<10 μm cuts, e.g., diamond knife/vibration cutting), and the cycle repeats — giving serial "chemical sectioning" with claimed sub-micron-class axial resolution (specification states 500–2000 nm; embodiments report 0.5–2 μm).

Representative dependent-claim subject matter (from the specification's preferred-feature clauses, which typically map to dependent claims):

• The sample "not emitting fluorescence" being either intrinsically non-fluorescent (protein/dye-marked) or reversibly quenched.
• Quenching via acid reagent, transition-metal-ion compound solution, or synergistic H⁺/metal-ion quenching.
• Activation by chemical reagent (alkaline solution, metal-ion chelating agent, or both) or by photochemical light penetrating only the surface layer.
• Protein types: pH-sensitive fluorescent proteins (EGFP, EYFP, pHuji, etc.), pH-stable DsRed, photoactivatable FPs (PAGFP, PAmCherry1), photoswitchable FPs (Dendra2, mEos3.1); organic dyes (Alexa 488/514/532/546).
• Metal ions (Cr²⁺, Mn²⁺, Fe²⁺/Fe³⁺, Co²⁺, Ni²⁺, Cu⁺/Cu²⁺) and chelating agents (EDTA-Na₄, 8-hydroxyquinoline, desferrioxamine, etc.).
• Resin-embedded samples; activation-light/excitation-light included angle of 0–90° (preferably 60–75°).

The working examples cover: Thy1-EGFP mouse whole brain (Embodiment 1); pHuji mouse brain with Na₂CO₃ reactivation (Embodiment 2); EYFP mouse brain with Na₂CO₃/glycerol (Embodiment 3); Rv-dg-mEos3.1 photochemical whole-brain imaging (Embodiment 4); PAGFP-expressing HeLa cells (Embodiment 5); Alexa 488 immunohistochemistry quenched with FeCl₃ and reactivated with EDTA-Na₄ (Embodiment 6); and DsRed with synergistic metal-ion/H⁺ quenching (Embodiment 7).

Uncertainty / caveats

• Exact verbatim claim set: I obtained the claim-ordered steps and the mirrored preferred-feature language, but I did not independently retrieve and verify a clean, complete copy of the granted claim listing (exact claim count and exact wording of each dependency). Treat the "plain-language" claim overview above as a faithful paraphrase grounded in the retrieved text, not as a verbatim quotation.
• Legal status boilerplate: Google Patents explicitly states its legal-status/ownership listings are assumptions, not legal conclusions; the same applies to the 2025 assignment entry.
• No litigation found: I found no CAFC 2026 docket entry, no district-court complaint, and no PTAB proceeding naming US 11,346,782. Absence of results in my search is not proof that none exists.
• Family: Corresponding family members include EP 3361237 A4 (not active/withdrawn), JP 6966435 B2 (active), CA 3004374 A1 (abandoned), and WO 2018/077114 A1 (ceased) — per Google Patents family data.

I'll search for litigation involving US patent 11346782 across patent litigation databases.

Let me search patent litigation-specific databases.

Let me search additional litigation-specific sources.

Litigation Search Results: US Patent No. 11,346,782

Summary Finding

No U.S. litigation (district court, ITC, or Federal Circuit) involving US Patent No. 11,346,782 was found in the sources searched. Likewise, no PTAB post-grant proceedings (IPR/PGR/CBM) associated with this patent were identified.

What the Searches Did Return

I note a specific warning that results for similar numbers can be misleading. Several distinct entities share the numeric string "11346782," and none of them relate to this patent:

• UK Companies House / The Gazette (London): "PIXEL BAR LEEDS LIMITED 11346782 (C2)" — a UK company registration number, unrelated to the patent.
• Estonian Business Register: "osaühing Vedas (registrikood: 11346782)" — an Estonian company registration number, unrelated.
• D. Del. case citation: "ZapFraud, Inc. v. Fantasia Networks, Inc., ... 2021 WL 1134687" — a Westlaw citation number, not the patent.

None of these are the patent at issue; they are coincidental numeric matches, and I am flagging them only to be transparent about why they appear.

Patent-Ownership Context (from the authoritative patent page, not litigation)

The only legal-proceedings-type events of record for US 11,346,782 are patent office assignment (ownership) records, not litigation:

Inventors: Shaoqun Zeng, Qingming Luo, Hanqing Xiong, Wenyan Guo, Xiaohua Lv
Original assignee: Huazhong University of Science and Technology
Current assignee: Wuhan Walter Billion Biological Co., Ltd (Wuhan Walter Billion Biological Co., Ltd / 武汉沃亿生物有限公司)
Priority date: 2016-10-31 · Filing date: 2017-10-20 (PCT national stage)

Important Caveats on Completeness

I must be explicit about the limits of this search rather than overstate confidence:

1. Databases not directly confirmed. I was unable to directly query/retrieve records from Unified Patents litigation caselist (portal.unifiedpatents.com), RPX Insight/Corp, PACER, Docket Navigator, and CourtListener for this specific patent number. My searches did not surface litigation docket entries for US 11,346,782, but the absence of a hit is not the same as a confirmed negative from those systems.

2. No plaintiff-side assertion observed. The patent has been under Chinese institutional/academic ownership, since 2025 held by a Chinese biotech instrument company (Wuhan Walter Billion). No U.S. infringement assertions by this patent owner were found in the available results.

3. A patent being "Active" with no litigation is entirely ordinary — most patents are never litigated.

Conclusion

Based on the searches performed: no known litigation involving US Patent No. 11,346,782 exists. The patent appears only in patent-office grant and assignment records (Google Patents/Global Dossier, USPTO Assignment), with no associated district-court complaints, ITC investigations, Federal Circuit appeals, or PTAB proceedings identified.

If you require an authoritative negative across PACER and Docket Navigator, I would recommend a direct docket-number and patent-number query in those systems, which was not fully accessible in this session.

I'll verify the structured data against live sources before writing anything.

Let me run a couple more targeted checks before concluding.

One more check for litigation or appeals that might not be indexed as PTAB proceedings.

Proceedings overview

Total AIA trial proceedings on file for US 11,346,782: zero — no IPRs, no PGRs, and no CBMs (CBM review was sunset for petitions filed after 2020-09-16 in any event), per the USPTO Open Data Portal structured block supplied in this prompt and confirmed by independent web search as of 2026-09-29; the bottom-line posture for a defendant is therefore "untested patent, zero petitioner-side estoppel, and no free invalidating roadmap — you would be the first to take a shot at it."

No proceedings to report

There is no proceeding number to list, and I am not going to invent one to fill the section template. Concretely, I found no IPR, PGR, or CBM bearing on US 11,346,782 in:

• The structured PTAB proceedings on file block (USPTO ODP ingest) — explicitly empty.
• Web search for the patent number paired with "IPR," "PTAB," "inter partes review," and "petitioner" — the only 11346782 hits were (a) a UK Companies House gazette entry for an unrelated company number, and (b) the patent's own Google Patents / FreePatentsOnline / Patents-Review pages.
• Web search on the assignee entity — "Wuhan Walter Billion Biological" returned zero results in connection with any PTAB or district-court proceeding.

For completeness on the peripheral items you asked me to chase, none of which exist because there is no trial:

• Judge panel: n/a — no panel has ever been constituted against this patent.
• Final Written Decision: none. No claim of US 11,346,782 has ever been canceled or confirmed at the PTAB.
• Settlement / termination: none.
• Federal Circuit appeal: none. I found no CAFC docket, and therefore no CourtListener or Federal Circuit opinion to cite. Because there is no FWD, there is nothing appealable.

Verification caveat (stated plainly rather than papered over): I could not run a paywalled docket service (Lex Machina, Docket Navigator) or query PTAB E2E directly, and the ODP ingest may lag a recently filed petition. A petition filed within roughly the last few weeks could exist and simply not be indexed. Before you rely on "zero," confirm at PTAB E2E and the Patent Center "Legal" tab for US 15/771,713. Everything below assumes the zero result holds.

Strategic summary

Claims status — every claim is UNTESTED. No claim of US 11,346,782 has been canceled, narrowed, or confirmed by the PTAB, so there is no "surviving claim" list to give you and no dead claim to attack a demand letter with. If opposing counsel asserts this patent, they are asserting the full, originally-granted claim set — including the broadest independent claim, which per the specification (see the "Preferably" clauses in the SUMMARY) is directed to any method that (1) activates surface-layer fluorescence of a protein- or dye-marked tissue sample that emits no fluorescence or only a specific waveband, (2) excites and images it, (3) cuts the surface layer off to expose an inactivated new surface layer, and (4) repeats to build a 3-D image. That is a method claim with a relatively mechanical deprivation-plus-repeat structure, and the specification is dense with enablement of highly specific chemistry (HM20 resin, sodium carbonate at pH 11.2–11.6, FeCl₃/EDTA-Na₄, PAGFP/mEos3.1/DsRed/Alexa 488). The gap between the narrow embodiments and the breadth of the claiming is exactly the kind of § 112 written-description and § 103 territory a first petitioner would probe — but nobody has. Note also that the patent text supplied to me does not include the issued claim set, so I am deliberately not quoting claim numbers; pull the claims from the Google Patents page before drafting anything.

Estoppel landscape — wide open. Because no petitioner has ever filed, § 315(e)(2) estoppel is inapplicable to every party. There is no petitioner, no privy, no real party in interest, and no RPI-related bar standing between you and the PTAB. You may file an IPR on any § 102/§ 103 ground, using any prior art, including art that a prior petitioner would have been estopped from raising. The only timing constraint you face is the ordinary § 315(b) one-year bar running from service of a complaint alleging infringement — so if a demand letter has matured into a served complaint, calendar the date.

Pattern signals — none, and that is itself the signal. There is no repeat petitioner, no defensive aggregator (I specifically searched for Unified Patents and found nothing tying it to this patent), no patent-owner appeal history at the CAFC, and no PTAB-driven claim-narrowing campaign. What the record does show is a patent that changed hands recently and is being monetized on a small scale: Huazhong University of Science and Technology publicly noticed a technology-transfer disposition on 2024-10-08 of a three-patent family (Chinese ZL201610967373.5, US 11,346,782 B2, and Japanese JP6966435B2) to 武汉沃亿生物有限公司 (Wuhan Walter Billion Biological Co., Ltd.) for RMB 1.01 million against an appraised value of RMB 1.0094 million (HUST/WNLO notice), and Google Patents records the corresponding US assignment recorded 2025-06-04. The term runs to an adjusted expiration of 2040-09-24 — roughly fourteen years of remaining tail risk against an assignee with modest apparent resources and, so far, no litigation or PTAB track record. China-side invalidation practice against the Chinese sibling is a separate matter before CNIPA and tells you nothing about the US claims; I did not find and will not assert any CNIPA outcome.

Recommended next steps

• Confirm the null result first. Before spending money, pull the "Legal" and "Post-Grant" tabs in Patent Center for application 15/771,713 and search PTAB E2E by patent number. A negative institutional record plus the ODP null is strong, but a same-week filing is the one plausible gap.
• No FWD to link or quote. You asked me to link to the FWD and quote its disposition if claims were invalidated. There is no FWD, so there is no disposition and nothing to quote — I am not going to fabricate a link to a decision that does not exist. The same goes for a CAFC opinion and any CourtListener cite.
• Treat the clean slate as the opportunity, not the risk. Zero prior proceedings means your IPR team gets first-mover advantage: no § 315(e)(2) estoppel, no adverse claim-construction record, no institution-denial precedent from your own forum that the Board can point back at, and no risk that the patent owner has already litigated its best art defenses to judgment. Run a full prior-art search now, before opposing counsel has any reason to expect it.
• If a complaint has been served, mark § 315(b). The one-year clock is your hard deadline. Given that the asserted claim set is untested and the specification's narrow chemical embodiments are the only enablement-supported disclosure, evaluate § 103 combinations built on the light-sheet/optical-tomography and tissue-clearing literature cited or admitted in the BACKGROUND, plus § 112 for the breadth of the "activating" limitations across the full range of claimed chemistries.
• Note the corporate posture. The assignee (Wuhan Walter Billion Biological Co., Ltd.) recorded its interest 2025-06-04 and acquired the family for about RMB 1.01 million. That is a small-entity, non-troll monetization profile. If you are already being asserted against, confirm the ownership chain under 37 C.F.R. § 3.73 and verify the real party in interest — the Chinese sibling patent and the JP6966435B2 counterpart may be held by the same or different entities, which matters for both standing and any global settlement discussion.

Bottom line: the absence of PTAB activity means the patent has never been stress-tested, not that it is strong. You face no estoppel and no roadmap, which cuts both ways — but for a defendant today, the actionable fact is that the invalidity case is entirely yours to build from scratch, and nobody has burned your best grounds yet.

I'll research the assignment record for US 11,346,782, focusing on USPTO Assignment Center records and the ownership chain.

Inventors

Pattern note — no red flag. All five inventors were HUST-affiliated at filing, and all five appear as assignors on the 2018-04-30 record conveying their rights to HUST (a university-employee obligation-assignment, not an abandonment). There is no evidence in the searched material of any inventor departing the original assignee within 12 months of filing, no inventor list truncation, and no inventor-as-individual enforcement activity. The inventor group is the same research group that produced the underlying academic publications and the HUST spinout product line (below). This is the ordinary profile of a university lab-derived patent, not a portfolio being divested ahead of a fire-sale.

Original assignee

Huazhong University of Science and Technology (HUST) — Wuhan, Hubei, China. Named as applicant on the PCT national-stage filing (2017-10-20) and as assignee on the issued patent; the inventors' 2018-04-30 assignment perfected that ownership.

• Primary line of business: public research university (education + research). Wuhan National Laboratory for Optoelectronics is one of its core research platforms.
• Did they ship a product embodying the claims? Not directly. HUST is an academic institution. Critically, however, the claims-embodying technology (MOST — "microscopic optical sectioning tomography" — and its fluorescence variant fMOST) was commercialized through a HUST spinout/licensee, not by HUST.
• Current status: Operating; HUST is not acquired or dissolved. It remains the original assignee of record until the 2025 transfer below.

Assignment timeline

I must be transparent: the underlying USPTO Assignment Center records exist (they are surfaced as legal events on Google Patents' authoritative page for this patent), but in this session I was not able to retrieve the reel/frame numbers, execution dates, or correspondent-of-record for either record. I am therefore reporting the events as documented, with reel/frame and correspondent explicitly marked "not retrieved," rather than inventing them. Verify at: https://assignmentcenter.uspto.gov/ (search patent number 11346782) or https://assignment.uspto.gov/patent/index.html.

• Recorded 2018-04-30 (execution date not retrieved — likely 2016–2017, near filing) — Reel/Frame not retrieved in this session

  • Conveyance: Assignment
  • Assignor: Luo, Qingming; Lv, Xiaohua; Xiong, Hanqing; Guo, Wenyan; Zeng, Shaoqun (all five named inventors)
  • Assignee: Huazhong University of Science and Technology
  • Correspondent: not retrieved — cannot assess recurrence; no finding either way
  • Context: Internal invention assignment — university employees conveying rights to their employer (perfection of applicant-of-record title).

• Recorded 2025-06-04 (execution date not retrieved) — Reel/Frame not retrieved in this session

  • Conveyance: Assignment
  • Assignor: Huazhong University of Science and Technology
  • Assignee: Wuhan Walter Billion Biological Co., Ltd (武汉沃亿生物有限公司)
  • Correspondent: not retrieved — cannot assess recurrence; no finding either way
  • Context: Commercialization / technology-transfer to an operating company (a HUST-linked spinout that has manufactured the MOST/fMOST instrument family since 2013).

Additional filing event (not a post-issuance assignment): 2017-10-20 PCT national-stage application filed naming HUST as applicant. Grant: 2022-05-31.

Timeline diagram

timeline
    title Ownership of US 11346782
    2016 : Priority date for the family
    2017 : PCT national stage filed by HUST
    2018 : Inventors assign rights to HUST
    2022 : Patent granted as US 11346782 B2
    2025 : HUST assigns to Wuhan Walter Billion

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. The 2025-06-04 assignee, Wuhan Walter Billion Biological Co., Ltd, is a verified operating company: founded March 2012 in Wuhan Optical Valley, ~50–150 employees, products in commerce (BioMapping 1000 / 3000 / 5000 / 9000 / 9500 MOST and fMOST instruments), reported revenue on the order of ¥40M by 2018, serving 100+ research institutes and hospitals, with multiple R&D generations shipped in 2016 and 2019. It has a real corporate address (Wuhan East Lake High-Tech Development Zone), not a registered-agent service, and no "IP/Holdings/Licensing/Ventures" suffix. There is no evidence of a single-member Delaware/Texas shell. (Supporting source: company profile at http://www.oebio.com/about.html and contemporaneous press coverage.)

2. Known asserter in the chain — NOT PRESENT. Neither assignee (HUST; Wuhan Walter Billion) matches any entity on the referenced NPE lists (Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Erich Spangenberg entities). No Unified Patents / RPX high-frequency-plaintiff entity appears anywhere in the chain.

3. Repeat correspondent across the chain — UNCLEAR (not assessable). The chain has only two records, and I was unable to retrieve the correspondent of record for either. With only two links and no correspondent data, there is no basis to assert recurrence; I am explicitly not treating this as a finding.

4. Cascading transfers — NOT PRESENT. Two recorded transfers span roughly seven years (2018 → 2025), with no chained LLCs, no <24-month sequencing, and no shared-assignee pattern. This is the opposite of cascade behavior.

5. Pre-litigation transfer — NOT PRESENT / UNSUPPORTED. No infringement suit naming this patent was identified in the prior litigation section, and none was found here. The 2025-06-04 transfer is ~16 months before today with no litigation to anchor it to; there is no docket to point to.

6. Bankruptcy fire-sale — NOT PRESENT. HUST is an operating public university; no Chapter 7/11, no receivership, no patent auction. The transfer is a negotiated academic technology transfer.

7. Privateering — NOT PRESENT. Privateering requires an operating company transferring to an NPE that asserts on its behalf against competitors. Here the direction is reversed in substance: the university transferred to an operating manufacturer that practices the technology itself. The well-documented history is the 2013 open-listing sale of the MOST patent package from HUST to Wuhan Walter Billion for ¥10M — a celebrated domestic technology-transfer transaction (first publicly listed university tech transfer under China's Ministry of Education-affiliated universities), with team/institution revenue sharing under Wuhan's "黄金十条" policy. This is commercialization, the inverse of privateering.

8. Defensive aggregator (anti-NPE) — NOT PRESENT. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. The patent is held by a practicing manufacturer, not a defensive pool.

Verdict

Operating-company assertion — with the important qualification that the "assertion" prong is unproven: no litigation involving this patent was found.

Justification: the chain terminates at Wuhan Walter Billion Biological Co., Ltd per the recorded 2025-06-04 assignment from Huazhong University of Science and Technology, and that assignee is a practicing manufacturer whose BioMapping 1000/3000/5000/9000/9500 instruments embody the claimed surface-layer chemical/optical tomography approach. There are zero NPE signals (no shell entity, no known asserter, no cascading transfers, no pre-litigation transfer, no fire-sale, no privateering, no defensive-aggregator termination), and the only other record — the 2018-04-30 inventor-to-HUST assignment — is a routine university employee assignment. The transaction is best characterized as legitimate university-to-industry technology transfer rather than any NPE/troll pattern.

Caveats / verification needed: (i) I could not retrieve reel/frame numbers or correspondents for either record in this session — both should be pulled directly from the USPTO Assignment Center to complete the file and to run the correspondent-recurrence check properly; (ii) no SEC filings bear on this chain because neither assignee is a U.S.-listed public company (Wuhan Walter Billion's disclosed A-round investor, 信中利资本 / China Equity Group, is a Chinese institution); (iii) no litigation or PTAB proceeding is of record, so nothing like "pre-litigation transfer" timing can be established.

USPTO Assignment Center (verify): https://assignmentcenter.uspto.gov/ — search patent number 11346782.

I'll research US Patent No. 11,346,782 directly and identify its cited prior art references.

Let me search for the specific patent's citation/reference sections and family information.

I found the citations section. Let me retrieve the full citation lists from the Google Patents page.

Prior Art Analysis: US Patent No. 11,346,782 B2

0. Direct USPTO / Google Patents Retrieval Confirmation

I located the specific patent — not a similar number. The record matches the authoritative text supplied:

1. ⚠️ Critical Framing Note Before the Analysis

Two important caveats govern everything below, and I want to flag them rather than bury them:

1. There are two distinct citation lists on the record, and they must not be conflated.

   • "Citations (3)" — the prior-art references cited on the face of this patent (i.e., the references the examiner/applicant listed against US 11,346,782 itself).
   • "Family Cites Families (9)" — references cited in sibling family members (the WO and CN counterparts), which Google Patents aggregates under a separate heading. These are not front-page citations of the US patent.

2. Retrieval completeness. In this session I was able to retrieve the "Citations (3)" list in full and only the first item of the nine-item "Family Cites Families" list. I could not retrieve the remaining eight family-citation entries or a scanned copy of the USPTO "References Cited" face page (Form PTO-892 / examiner-cited list). I am therefore not claiming the list below is exhaustive. Where I am inferring rather than reading, I say so.

3. Citation ≠ anticipation. A reference listed on a patent's face is a citation, not a finding of anticipation. For §102, a reference must (a) qualify as prior art as of the 2016-10-31 priority date and (b) disclose every limitation of a claim. I map below to the closest claims and state the gaps explicitly.

Because I could not obtain the granted claim set verbatim in this session, I map each reference to claims using the specification's "Preferably" chain (Summary section), which in this patent tracks the claim structure closely: an independent method claim (activating → imaging), plus dependent claims adding cutting/repeat/reconstruction, reversible quenching, chemical vs. photochemical activation, alkaline/chelating activation, and the submicron axial resolution.

2. Front-Page Citations of US 11,346,782 ("Citations (3)")

All three predate the 2016-10-31 priority date, so all three are facially eligible as §102 prior art.

Reference 1 — WO 2016/145366 A1 (the closest art)

Description: Discloses an automated system for serial sectioning of a tissue block coupled with staining and optical imaging, layer-by-layer, and reconstruction of a 3D volume from the serial 2D images. This is the paradigm of "cut → treat → image → repeat → register" — the same mechanical loop recited in the patent (FIGS. 1–2; the "activating-imaging-cutting off" cycle).

Potential §102 relevance:

• Potentially anticipatory of the independent method claim's framework (the activating/treating-surface → imaging-surface → cutting-surface → repeat → overlap-images-to-3D sequence), if the reference's "staining" step is read as an "activating" step.
• Likely NOT anticipatory of the characterizing limitations of the patent, which require that the sample does not emit fluorescence (or emits only specific-waveband fluorescence) before activation and that activation be confined to a surface layer by chemical permeation or shallow-penetrating activating light. Serial staining adds signal; it does not presuppose a pre-quenched, reversibly-silenced sample. This distinction is the patent's stated point of novelty (Summary, beneficial effects (1)–(4)).
• Best characterized as: the primary §102/§103 reference for the cut-and-image architecture, and the reference a challenger would lead with — but the reversible-quenching/reactivation core would have to be supplied by a secondary reference.

Reference 2 — US 2010/0330578 A1

Description: Relates to thermo-optical characterization of molecules using fluorescent labels/dyes, exploiting temperature-dependent fluorescence quenching and detection of fluorescence changes.

Potential §102 relevance:

• Potentially relevant to dependent claims reciting that fluorescence is reversibly quenched and later re-activated — this reference demonstrates that fluorophore emission can be switched off/on by an external physicochemical stimulus. It is the type of teaching an examiner might cite against a broad dependent claim to "reversibly quenching the fluorescence … by steeping in a chemical reagent."
• NOT anticipatory of any claim as a whole: it is a nucleic-acid characterization method, not an imaging/tomography method, and contains no surface-layer activation, no cutting, and no tomographic reconstruction. At most a §103 secondary reference.

Reference 3 — CN 101042343 A

Description: Discloses coordination complexes / fluorescent probe systems for detecting antioxidant radical-scavenging reactions, i.e., fluorescent molecules whose emission is modulated via metal-ion complexation / redox chemistry — the same chemical logic the patent uses (metal-ion–fluorophore ring formation quenching emission; chelator restoring it — patent FIGS. 6–7, and the Alexa 488 / DsRed embodiments).

Potential §102 relevance:

• *Potentially relevant only to the dependent claims directed to reversible quenching via transition-metal ions and reactivation via a metal-ion chelating agent (transition-metal species Cr²⁺, Mn²⁺, Fe²⁺/Fe³⁺, Co²⁺, Ni²⁺, Cu⁺/Cu²⁺; chelators EDTA-Na₄, desferrioxamine, etc.).
• NOT anticipatory of any claim as a whole: it discloses a detection chemistry, not a tomographic imaging method with serial surface activation and mechanical sectioning. §103 secondary-reference material at best.

3. "Family Cites Families (9)" — Sibling-Family Citations

These appear under Google Patents' family citation heading because they are cited in the WO/CN siblings, not on the US face page. I retrieved only the first entry.

Reference 4 — US 7,372,985 B2 (retrieved; remaining 8 not retrieved)

Description (inferred from the truncated title; flagging this as inference): Appears to concern automated volumetric tissue imaging — consistent with microtome-based serial sectioning plus optical imaging and 3D reconstruction.

Potential §102 relevance:

• Potentially relevant to the independent claim's cutting-and-reconstruction architecture (mechanical surface removal + imaging + volumetric reconstruction) and to any dependent claim reciting a cutting system capable of super-thin cutting (the patent specifies diamond-cutter/vibration cutting within a 10 µm thickness).
• NOT anticipatory of the fluorescence-quenching/reactivation core. Treat as §103 background/secondary art.

⚠️ Remaining 8 family citations: Not retrieved. I will not guess at them.

4. Summary Table — Citation Set Retrieved

5. Analytic Bottom Line

• No single one of the retrieved references appears, on its face, to anticipate the full scope of the patent's characterizing claims. The patent's stated novelty is a conjunction: (a) a sample that is non-fluorescent (or emits only specific-waveband fluorescence) before activation — either intrinsically (photo-controlled FPs) or by reversible chemical quenching; (b) surface-limited activation by chemical permeation or shallow-penetrating light; (c) serial cut → reactivate → image → repeat; and (d) overlap to reconstruct a 3D volume at submicron axial resolution.
• WO 2016/145366 A1 supplies (c) and (d) and is the strongest §102 candidate; it conspicuously lacks (a) and (b)'s reversible-quenching logic.
• US 2010/0330578 A1 and CN 101042343 A supply pieces of (a) — reversible/chemical switching of fluorophore emission — but nothing of the imaging architecture.
• US 7,372,985 B2 supplies background for (c)/(d) (volumetric sectioning-and-imaging).
• The realistic validity challenge is therefore a §103 combination (e.g., WO 2016/145366 A1 as primary + a reversible fluorescence-quenching reference as secondary), not a clean §102 anticipation by any single reference retrieved.

6. Explicit Limitations of This Analysis

1. I retrieved the 3 front-page "Citations" and only 1 of 9 "Family Cites Families" entries; 8 family citations remain unchecked.
2. I could not retrieve the USPTO face-page "References Cited" list (PTO-892) or the PCT/CN International Search Report's "Category X/Y/A" designations for PCT/CN2017/106964. The ISR category designations would be the single most probative artifact for ranking true §102 (X) vs. §103 (Y) candidates, and I flag their absence rather than substitute speculation.
3. The granted claim set was not retrieved verbatim; claim mapping above follows the specification's preferred-embodiment chain.
4. Descriptions for US 7,372,985 B2 (truncated title) and the remaining family citations are marked as inference or unretrieved, respectively — not asserted as fact.

Recommended next step for a definitive answer: pull the USPTO PatentCenter "References Cited" tab for application 15/771,713 and the WO 2018/077114 A1 International Search Report, which will supply the examiner's complete citation list and the X/Y/A relevance categories — the two data points this session could not fully reach.

I'll start by trying to retrieve the prior-art citation list for this patent, since the task directs me to use the "Prior Art section" — and the patent text provided to me does not visibly contain a citations list.

Now let me search for the specific prior-art references relevant to the claimed subject matter, including the sectioning-imaging art and photoactivation art.

Let me search for the international search report for the family (WO 2018/077114) and additional prior-art areas.

Obviousness Analysis — US 11,346,782 B2 ("Tomographic imaging method")

0. Threshold note on the "Prior Art section"

The full patent text supplied to me does not contain a citations/prior-art table. The Google Patents page text I was given includes the definitions, classifications, drawings list, description, and the Background section, but not the "(56) References Cited" / "Citations" tables. That is a limitation I will not paper over.

I therefore retrieved the family citation list indirectly — from the Google Patents page of the priority document CN 106501228B / CN106501228A (same HUST family, same title 一种层析成像方法), which does expose the citations table for the family. That list was truncated in the retrieved snippet (it ends mid-entry at "CN102…"), so the list below is partial and I could not verify it against the US 11,346,782 page itself. Treat it as the best available reconstruction of the "Prior Art section," not a certified copy.

The same page also exposes a "Cited By" table (later art — not § 102 art here): WO2018077114A1, CN110458923A, US11397179B2 (Bosch, "pH-modulated imaging of targets close to a solid surface," 2022-07-26), CN117405636B.

Everything below is an analyst opinion on prima facie obviousness. It is not a legal conclusion, and I am not the examiner.

1. Governing standard and critical date

Framework: Graham v. John Deere, 383 U.S. 1 (1966); KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) (any "articulated reasoning with some rational underpinning" suffices; "a finite number of identified, predictable solutions" → obvious to try); MPEP §§ 2141–2145 (rationales: known-method combination / predictable result; simple substitution; known technique to improve similar device in the same way; design incentive or market force).

Important consequence of the date: the closest reference is the inventors' own 2014 Nature Communications paper (Xiong, Lv, Luo, Zeng are named inventors). Because it published ~2.4 years before the 2016 priority date, the § 102(b)(1)(A) grace period does not reach it. It is therefore § 102(a)(1) prior art notwithstanding the common inventive entity, and it may be combined with other art for § 103. This is the single most important procedural fact in this analysis.

2. Independent claim 1, decomposed

Per the previously generated claim summary (which the summary itself flags as a faithful paraphrase, not verbatim — I could not independently verify the granted text), claim 1 recites:

Dependent/preferred subject matter (from the specification's "preferably" clauses): reversible quenching (acid; transition metal ion; H⁺ + metal ion synergy); activation by alkaline solution, metal-ion chelator, or both; or photochemical activation by surface-penetrating light; EGFP/EYFP/pHuji/DsRed/PAGFP/PAmCherry1/Dendra2/mEos3.1/Alexa 488-514-532-546; Cr²⁺/Mn²⁺/Fe²⁺/Fe³⁺/Co²⁺/Ni²⁺/Cu⁺/Cu²⁺; EDTA-Na₄/8-hydroxyquinoline/desferrioxamine; resin embedding; activation-to-excitation included angle 0–90° (preferably 60–75°); submicron (500–2000 nm) axial resolution.

3. Prior art identified (dates verified from search results)

4. Combination 1 (primary): PA-1/PA-2 + PA-3 (or PA-4/PA-6..PA-8) → chemical-route claims

Proposed rejection: Claim 1 (and the alkaline-solution, resin-embedding, registration, and iteration dependent claims) obvious over PA-1 or CN105021431A in view of PA-3 (MOST).

Element mapping:

Motivation to combine (KSR rationales):

1. Known problem, known solution (KSR; MPEP 2144.04/M.P.E.P. 2143(a)): PA-1 concludes that CR "provides a turning point for the imaging of fluorescent protein-labelled specimens after resin embedding." The pre-existing obstacle to FP-based whole-brain imaging was precisely that resin blocks quench FPs; PA-1 solves the chemistry, PA-3/PA-4 provide the already-routine volumetric acquisition loop. Combining them is using a known solution in the known architectural context.
2. Design incentive / market force: whole-brain connectomics (PA-3's own stated motivation: "brainwide mapping of neural circuits") creates strong pressure to replace Golgi staining with multicolour transgenic FP labelling. PA-3 itself flags the desirability of "multi-labeled transgenic animal models."
3. Simple substitution of a known element (MPEP 2144.03): swap Golgi/bright-field chromogenic contrast (PA-3) for CR-reactivated fluorescence (PA-1) within an unchanged cut-image-stack machine.
4. Predictable result: increased fluorescence contrast from CR + 1-μm mechanical sectioning → axial resolution of the order of the section/activation thickness. That the axial resolution of an activation-depth-limited serial-sectioning scheme is ~1 μm is arithmetically, not surprisingly, related to the variables recited.
5. Why surface-limited rather than full-block reactivation is obvious: if the entire resin block reacted fully with alkali, the sample would emit out-of-focus background — the exact defect PA-3's own optical design (confocal/reflected illumination) exists to suppress. One of skill thus has a concrete reason, supplied by the art itself, to confine reactivation to the imaged surface (short soak, oblique application, applying reagent only to the cut face — the patent's own description adds the hydrophobic-coating expedient, a conventional technique).

Note that the non-mechanically-cut-face hydrophobicity trick recited in the specification is textbook surface-tension behaviour and would likely draw an "obvious design choice" rationale.

5. Combination 2 (alternate): PA-11 + PA-3/PA-4 (+ PA-1 for the "reversibly quenched" limb) → photochemical-route claims

Proposed rejection: Claims reciting photochemical activation (PAGFP / mEos3.1 / photoswitchable FPs, surface-penetrating activation light, 0–90° angle) obvious over PA-11 (PAGFP) in view of PA-3 or PA-4, optionally further in view of PA-1.

Rationale:

• PA-11 supplies the "off → on" (or green → red, for mEos-family) photoswitchable label whose "off" state satisfies the preamble and whose localized activation is the activating step L1.
• The sole remaining question is why one would confine activation to a surface layer. The art supplies this: (i) short-wavelength (~405 nm) light is strongly attenuated in tissue (Beer–Lambert), so a UV activation beam on a cut block face naturally activates only the outermost microns — the patent's own explanation; (ii) oblique illumination further reduces penetration (the specification's "the smaller the angle is, the stronger the surface reflection is"), and an included angle of 60–75° between activation and excitation beams is an ordinary geometric choice in the finite 0–90° design space (MPEP 2145; In re Boesch-type "design choice" reasoning); (iii) if the whole block activated, the resulting out-of-focus background defeats the purpose.
• PA-3/PA-4 supply the iterate-cut-image-stack architecture and the 3D reconstruction step.
• Obvious to try: the field contained a finite, identified set of switchable labels (photoactivatable FPs, photoswitchable FPs, pH-sensitive FPs, reversibly metal-quenched dyes). A person of skill, faced with the resin-quenching problem documented by PA-1, would predictably select one of these and pair it with a sectioning loop.

6. Combination 3 (alternate): PA-1 + PA-10 (+ PA-9) → dye / metal-ion / chelator claims

Proposed rejection: Claims reciting organic fluorescent dye (Alexa 488/514/532/546) marked tissue, transition-metal-ion quenching, and chelator (EDTA-Na₄, desferrioxamine) reactivation obvious over PA-1 in view of PA-10 (and/or known coordination-chemistry quenching of xanthene/fluorescein dyes by Cu²⁺/Fe³⁺/Ni²⁺).

Rationale:

• The rule of the method — "make it non-fluorescent first, then switch on only where you will image" — is fully supplied by PA-1.
• PA-10 (cited against this very family) demonstrates ligand/metal-ion complexation as a reversible fluorescence on/off switch, and chelator sequestration as the "off→on" trigger — the exact mechanism the specification attributes to EDTA-Na₄ and desferrioxamine.
• That paramagnetic/transition-metal ions quench organic fluorophores, and that strong chelators reverse it, is textbook coordination chemistry; the recited metal list (Cr²⁺, Mn²⁺, Fe²⁺/³⁺, Co²⁺, Ni²⁺, Cu⁺/²⁺) is a genus of routine candidates.

7. Claim-by-claim vulnerability assessment (analyst's estimate)

8. Anticipated counter-arguments by the patentee (and my assessment)

1. "No reference teaches or suggests deliberately limiting activation to a surface layer; PA-1 teaches soaking the whole block for maximum signal — arguably a teaching away from partial reactivation."
   Assessment: This is the strongest argument and the one most likely to carry weight at the EPO/PTAB. PA-1 reports an 11.8× gain and 98 % preservation by full CR; a purist reading is that PA-1 optimizes complete reactivation. Rebuttal available to the examiner: PA-1 itself states the buffer penetrates the resin and its imaging is explicitly within a 4-μm surface layer, and PA-3's architecture requires that any signal outside the imaging plane be suppressed. Whether that rebuttal succeeds depends on how express the "only the surface layer" teaching is; on the record I retrieved, it is inferred, not express — a genuine weakness in a prima facie case.

2. "The specific combination (chemistry + serial sectioning + commercial sub-micron throughput) produced unexpected results."
   Assessment: Objective indicia are legally available (KSR; Graham factor 4). I found no evidence in this session of unexpected-results data, praise, licensing-for-validity, or commercial-success-with-nexus attributable to the claimed method specifically (the 2025 assignment to Wuhan Walter Billion Biological Co., Ltd. is an ordinary ownership transfer, not a validity indicium). Absent such evidence, this argument fails for lack of proof.

3. "The claims require a specific chemical means of contrast generation, not the optical sectioning of MOST/STP."
   Assessment: Weak. PA-3 expressly states "MOST is capable of fluorescence imaging" and PA-1 supplies the chemical means; the combination is the whole point.

4. "§ 102(b) grace period protects the inventors' own 2014 paper." Assessment: No. Published 2014-06, >1 year before 2016-10-31 → outside § 102(b)(1)(A). This argument is unavailable.

9. Bottom line

• Most likely § 103 rejection: Xiong et al. 2014 (PA-1) and/or CN105021431A (PA-2), in view of Li et al. 2010 (MOST, PA-3) and/or Ragan et al. 2012 (STP, PA-4) or US 7,372,985 / US 2009/0041316 / WO 2010/021744 (PA-6/7/8), against independent claim 1 and the alkali/chelation/resin-substrate/metal-ion/angle dependent claims. Rationales: known-problem/known-solution, simple substitution, design incentive (whole-brain connectomics; the resin-quenching problem acknowledged in the patent's own Background), and predictable results from routine optimization of permeation time and angle.
• Second, structurally different rejection (photochemical limb): Patterson & Lippincott-Schwartz 2002 (PA-11) in view of PA-3/PA-4, plus PA-1 for the reversible-quenching preamble.
• Hardest limitations to invalidate: the DsRed H⁺/transition-metal-ion synergetic quenching and alkalinous-chelator reactivation set, and the Alexa-dye-specific Fe³⁺/EDTA set — these are narrow, mechanism-specific, and the closest retrieved art does not expressly disclose them. Everything framed as a result ("submicron axial resolution") or an arbitrary loop-exit condition ("until remaining thickness < surface-layer thickness") should be given little patentable weight.

10. Explicit caveats

1. Verbatim claims not verified. This analysis rests on the previously generated paraphrase of the claim set plus the specification's "preferably" clauses. The exact wording, dependency structure, and claim count of US 11,346,782 were not independently confirmed in this session. A real invalidity opinion requires the granted claim text.
2. "Prior Art section" only partially retrieved. The citation list I used came from the CN family page (CN106501228A) and was truncated (cut off at "CN102…"); the US 11,346,782 page text I was given contained no citations table at all. Additional cited references may exist that materially change the analysis — in either direction.
3. PA-11 (Patterson & Lippincott-Schwartz 2002) was not re-verified by search in this session (the query aborted); it is stated from training knowledge, corroborated by the patent's own FIG. 3 description of PAGFP's 405 nm activation and ~100× enhancement.
4. Dates for CN105021431A (2015-11-04) and CN105866079A (2016-08-17) are taken from the retrieved Google Patents citations table; if CN105021431A's publication date were later than shown, the § 102(b)(1)(A) analysis would change (its disclosure would still be corroborated by PA-1, which is unambiguously prior art).
5. I found no litigation, no PTAB proceeding, and no reexamination involving this patent, consistent with the earlier litigation section; nothing in this analysis reflects an adjudicated validity holding.