US 4216245

I'll search for this specific patent number in the sources you named.

Let me run a few more targeted checks on litigation/assignment status.

Search Results Summary — US Patent 4,216,245

Important caveat on the searches you requested: I searched broadly for a United States Court of Appeals for the Federal Circuit (CAFC) 2026 docket and for USPTO litigation records tied to this patent number. I found no CAFC 2026 case, IPR/PGR, or district court action involving U.S. Patent No. 4,216,245. My searches were general web searches, not a direct PACER/CAFC docket or USPTO PatentCenter query, so this is not an exhaustive docket clearance — treat it as "no evidence found," not as a certified negative. See "Litigation / Status" below for why that is expected.

Bibliographic Data

Family / priority chain (as printed in the patent): This application is a continuation-in-part of Ser. No. 779,824, filed Mar. 21, 1977, now abandoned, which was a divisional of Ser. No. 701,403, filed June 20, 1976, now U.S. Pat. No. 4,046,513.

⚠️ Flagged inconsistency (not corrected): The printed text gives the grandparent application's filing date as "June 20, 1976" while also stating it issued as U.S. 4,046,513, which the record shows issued Sept. 6, 1977 (a similar document, US 4,046,513, is listed in the "Similar Documents" table). A grant roughly 14 months after filing is unusually fast for that era. The reference date is reproduced above exactly as printed; I am not correcting it.

Minor source discrepancy: A Unified Patents portal entry rendered the same patent as priority date 1978-07-24 with assignee Bayer AG. The authoritative full patent text and PubChem both give 1978-07-25 and Miles Laboratories (PubChem: inventor "JOHNSON LEIGHTON C," assignee "MILES LAB"). I have treated the full patent text as controlling.

Abstract (as printed)

"A test device for determining the presence of a constituent in a sample, and a method for making it are disclosed. The test device comprises reactants (e.g. reagents, enzymes, etc.) incorporated with a carrier matrix such that when the device is wetted with a test sample, the reactants and the constituent react to produce a detectable response. The reactants are positioned separately from each other on the matrix in substantially, discrete, non-contacting areas. Hence, reactants are maintained substantially separate from each other until the test device is wetted with the sample."

Plain-Language Overview of the Independent Claims

Claim 1 — Independent (the "any printing method" claim)
A method of making a "dip-and-read" diagnostic test device (e.g., a reagent strip). You take a carrier matrix and load it with a reagent system of two reactants that react with each other only when the sample analyte is present, producing a detectable (color) response. The improvement is the manufacturing step:

1. Formulate a first ink containing reactant #1 and a second ink containing reactant #2;
2. Print the first ink onto the matrix as a first array of discrete impressions;
3. Print the second ink as a second array of impressions that is at least partially interspersed with the first array, but the impressions stay substantially out of contact with each other.

The point: the two mutually reactive reagents sit side-by-side on the same strip without touching, so they cannot prematurely interact during storage — they only mix when the sample wets and diffuses the matrix.

Claim 6 — Independent (the silk-screen-specific claim)
The same method as Claim 1, but limited to silk screening both the first and second inks into the interspersed, substantially non-contacting arrays.

Dependent claims (for completeness):

• Cl. 2 — printing by offset.
• Cl. 3 — printing by screening.
• Cl. 4 — printing by gravure.
• Cl. 5 — first ink printed as parallel stripes, second ink printed in stripes mutually parallel to and between the first.
• Cl. 7 — the first and second patterns comprise dots.
• Cl. 8 — the two patterns together form a plurality of parallel stripes, alternately positioned.

Supporting Disclosure Highlights

• Objective: extends shelf life by physically separating ordinarily incompatible reagents on the strip itself. The specification states strips so made "have excellent shelf life and are vastly superior in this respect to present commercial strips containing the same reactants."
• Geometry guidance: circular dots are described as optimum for packing density and diffusion; dissimiliar dots may be equal or unequal in number; patterns may be irregular, of mixed shapes, or made denser in one region (FIGS. 1–5).
• Worked examples: Ex. 1 (alternating stripes via a 14-channel dispensing head, cellulose-acetate/acetone vehicle inks, tested against 100 mg% albumin); Ex. 2 (offset/halftone rubber-plate dot printing — 30-mil "periods," 64 per in²); Ex. 3 (silk-screen dot printing — 25-mil dots at 250/in² and 40-mil dots at 125/in² on Trycite® polystyrene).
• Also disclosed: entrapment of enzymes (e.g., glucose oxidase) in acrylamide/N,N-methylenebisacrylamide gel inks with potassium persulfate photoinitiator, cured in situ; matrices of paper, plastic, or combinations; white/matte reflective surfaces; diluents (chloroform, carbon tetrachloride, benzene) and wetting agents (diglycol laurate).
• Cited prior art of record (6 references): US 3,127,281; US 3,549,328; US 3,666,421; US 3,975,162; US 3,996,006; US 4,087,332.
• Notable related document: US 4,046,513 ("Printed reagent test devices and method of making same"), the grandparent in this family.

Litigation / Status

• Status: Expired – Lifetime; anticipated expiration 1997-08-05. Given that date, any assertion in 2026 would face both expiration and the 35 U.S.C. § 286 six-year damages look-back bar. Practical 2026 CAFC exposure is therefore effectively nil.
• No CAFC 2026 docket activity found for this patent number, and no IPR/PGR identified. Again, this reflects my available search results only — for a definitive answer you would need a direct PACER/CAFC docket and USPTO PatentCenter/PTAB query.

Confidence / Uncertainty

• High confidence in the bibliographic data, abstract, and claim text above — they come from the authoritative full patent text you supplied, corroborated by PubChem and FreePatentsOnline.
• Low confidence / unverified: (a) the exact grandparent filing date (see flagged inconsistency); (b) the chain of title from Miles Laboratories, Inc. to Bayer (Miles was acquired by Bayer AG in 1979, and the Miles name was retired in 1995, so "Bayer Corp" as current assignee is plausible but I did not verify a recorded assignment); (c) the absence of any 2026 CAFC activity — this is a negative search result, not an authoritative docket check.

Sources: Google Patents US4216245A (https://patents.google.com/patent/US4216245/en); PubChem US-4216245-A (https://pubchem.ncbi.nlm.nih.gov/patent/US-4216245-A); FreePatentsOnline (https://www.freepatentsonline.com/4216245.html); USPTO.report (https://uspto.report/patent/grant/4216245).

I'll search for litigation involving US patent 4216245.

Litigation Search Report — U.S. Patent No. 4,216,245

Patent identified (literally, as requested): US 4,216,245 A — "Method of making printed reagent test devices." Application No. 05/927,892, filed July 25, 1978; granted August 5, 1980. Inventor: Leighton C. Johnson. Original assignee: Miles Laboratories, Inc.; current listed assignee: Bayer Corp. Legal status per the Google Patents record: "Expired – Lifetime," with an anticipated expiration date of August 5, 1997.
Source: https://patents.google.com/patent/US4216245/en

Bottom line

I found no litigation — district court, Federal Circuit, ITC, or PTAB — involving U.S. Patent No. 4,216,245. No case name, docket number, court, or filing date can be reported for this patent because none was located. I am stating this as a negative finding, not as a certified that no case ever existed.

What I searched and what came back

Distinctly different identifiers that my searches surfaced — these are NOT US 4,216,245 and should not be conflated with it:

• JP 4216245 B2 (Japanese Patent No. 4216245, Fanuc, "Control device for die cushion mechanism," registered 2008-11-14) — unrelated subject matter.
• DE 42 16 245 (German application, Jungheinrich AG, 1992) — unrelated.
• EP 0 570 658 B1, which claims priority to DE 4216245 — unrelated.
• FR trademark 4216245 (Calvados Christian Drouin) and Argentine Acta 4216245 — unrelated.
• US 4,216,245 A appears as a cited reference in EP 1 664 332 B1 (cited as "US 4216245 A, Johnson"), i.e., a prior-art citation, not an assertion in litigation.

Why the absence of litigation is consistent with the record

Three facts from the authoritative patent text support the negative finding:

1. Terminal disclaimer of term by expiry. The Google Patents legal-status data shows anticipated expiration on August 5, 1997. Any suit on this patent would necessarily predate that date — i.e., a 1980s–mid-1990s filing window, a period for which PACER coverage of older district court dockets is incomplete and for which no reliable free aggregate exists.
2. Narrow, method-only claim set. All eight claims are method claims directed to the making of a dip-and-read test device (claims 1 and 6 are the independent claims; claims 2–4 and 7–8 depend from them; claim 5 is the stripe-printing variant). Method-of-manufacture claims of this kind were historically enforced primarily by threatening letters or by suits that are hard to index, and infringement by an imported finished strip was difficult to detect.
3. Family relationship. The patent is a continuation-in-part of Ser. No. 779,824 (filed Mar. 21, 1977, now abandoned), which was itself a division of Ser. No. 701,403 (filed June 20, 1976), now US 4,046,513 ("Printed reagent test devices and method of making same"). If Miles/Bayer enforced this technology family, the '513 patent would likely have been the more natural vehicle. My searches did not confirm any suit on the '513 patent either, but I did not run an exhaustive check on that separate patent number.

Caveats on methodology

• I could not directly query PACER's full historical docket archive, Docket Navigator, or Lex Machina — those are paywalled and not reachable through the general web searches performed. My finding rests on publicly indexed sources (Google Patents, Unified Patents portal, CourtListener, Justia dockets, and general web indexing).
• Because US 4,216,245 expired in 1997, any PTAB proceeding (IPR/PGR/CBM) is chronologically impossible — the AIA trial mechanisms post-date the patent's expiration by roughly fifteen years.
• If you need a certified negative, the defensible route is a paid Docket Navigator or Lex Machina search on the literal string 4,216,245 (both patents-in-suit and asserted-patent fields), plus a manual pull of Miles Laboratories / Bayer as plaintiff from 1980–1997.

No litigation is known for U.S. Patent No. 4,216,245. I am explicitly flagging this as a limitation of the search rather than a guarantee, because the relevant filing window predates comprehensive free public docket coverage.

PTAB Proceedings — US 4,216,245 ("Method of making printed reagent test devices")

Canonical source check. The structured "PTAB proceedings on file" block from the USPTO Open Data Portal returns no AIA trial proceedings for US 4,216,245. I ran independent web searches (PTAB E2E / PTActs, docket aggregators, CourtListener-indexed CAFC opinions, Google Patents/PubChem family data) and found no IPR, PGR, or CBM petition, institution decision, FWD, or appeal naming this patent. Nothing surfaced that contradicts the ODP.

Proceedings overview

Total AIA trial proceedings on file: 0 (0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denials) — and that zero is structural, not coincidental: US 4,216,245 issued 1980-08-05 and its term expired 1997-08-05 (Google Patents: "Anticipated expiration," status "Expired - Lifetime"), roughly 15 years before the AIA created IPR/CBM review (2012-09-16) and 16 years before PGR (2013-03-16). Bottom line for a defendant: there is no PTAB record to mine, and there never can be one — but you also don't need one. The patent is expired, so your defense is statutory (no enforceable term, no recoverable damages window) rather than an IPR-based invalidity play.

Per-proceeding detail

None. There is no proceeding to report. I will not manufacture one. For completeness, here is exactly what I checked and what I ruled out:

⚠️ Misattribution flag — do not confuse this with a live 2026 trial

A search surfaced IPR2026-00059 (patent owner's request for discretionary denial under Fintiv and § 325(d)) in which the briefing repeatedly refers to "the challenged '245 Patent." That is not US 4,216,245. The technology is unrelated (a server-based vehicle reservation system; the art discussed is Zaid and Mottla; the briefing addresses a Markman order in parallel district court litigation). A late-digit "245" patent — most plausibly a 7,xxx,xxx number — is the subject there. I did not retrieve a claim of the petition confirming the full number, so I am flagging this as a number collision, not reporting it as a proceeding against 4,216,245. If a demand letter cites "the '245 patent," confirm the full seven-digit number and the issue date before you accept or reject the mapping.

Source for the flag: PTActs public petition document, https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1558625](/patent/1558625)/download-documents

Strategic summary

Claim status: every claim is UNTESTED at the PTAB — and untouchable. Claims 1–8 (the whole claim set: independent claims 1 and 6 covering the printing methods; claims 2–4 to offset/screen/gravure; claim 5 and claim 8 to alternating parallel stripes; claim 7 to dot patterns) have never been before the Board. None is canceled; none is affirmed. The reason is temporal: AIA trial jurisdiction postdates the patent's 1997-08-05 expiration. PGR was categorically unavailable because it requires at least one claim with an effective filing date on or after 2013-03-16 (AIA § 3(n)(1)) — this patent's priority runs to 1976 via its parent, US 4,046,513. CBM review was categorically unavailable because the claims are directed to a diagnostic reagent test strip, not a "covered business method" tied to a financial product or service — and the transitional CBM program has since sunset (no CBM petitions accepted for filing on or after 2020-09-16). IPR is the only vehicle that could theoretically have reached an expired patent, but with no live infringement suit there was never a § 315(b) trigger and no economic reason to file one.

Estoppel landscape: moot, and that cuts in your favor. There is no § 315(e)(2) estoppel because there is no petitioner, no instituted ground, and no final written decision. That means no prior-art ground is off the table — but you also don't need the art. Your controlling defenses are temporal and remedial, not technical: (1) the exclusive right ended 1997-08-05, so there is no act of infringement to enjoin today; (2) 35 U.S.C. § 286 caps damages at six years before the complaint, and a patent that expired in 1997 cannot have any infringing acts inside that lookback unless infringement is ongoing — impossible for an expired right; (3) any 1990s-era claim is barred by limitations and laches. The related parent, US 4,046,513 ("Printed reagent test devices and method of making same," granted 1977-09-06), and the intervening CIP application 779,824 (abandoned) are likewise long expired — check them too if a demand letter cites a family member.

Pattern signals: none. No serial petitioner (no petitioner at all). No patent-owner appeal conduct — the patent owner, Miles Laboratories (now Bayer Corp per the ODP current-assignee field), never had a PTAB case to appeal. No defensive aggregator (Unified Patents, RPX, etc.) appears anywhere in the chain. This is a pre-AIA, pre-PTAB patent whose entire post-grant enforcement life predates the trial regime, not a patent that was challenged and hardened. Its heavy citation footprint (193 cited-by references, including Affymetrix array work, i-STAT biosensors, and Abbott Diabetes Care sensors) reflects its technical influence on printed-reagent and array fabrication, not litigation activity.

Recommended next steps

1. If you received a demand letter citing "US 4,216,245": treat it as a red flag on the sender's diligence. Verify the full number and issue date at https://patents.google.com/patent/US4216245/en (publication date 1980-08-05; legal status "Expired - Lifetime"; anticipated expiration 1997-08-05). A letter asserting this patent — or its parent US 4,046,513 — in 2026 is asserting an expired right. Respond with the expiration date and § 286, not with an IPR budget.
2. Confirm the ODP read yourself before relying on it. Pull the patent's trial history via PTAB E2E (https://ptab.uspto.gov) and the Patent Center trial/appeal tabs, and pull the full file history (IFW) to close the one gap I could not verify: whether any ex parte reexamination was ever filed. If your analysis turns on the absence of any post-grant challenge, the IFW is the authoritative source and I have not reviewed it.
3. Do not file an IPR to "clear" this patent. There is no institution decision to win, no FWD to appeal (no Article III path), and no estoppel benefit to obtain against a dead right.
4. If a live 2026 IPR is the actual concern, re-check the full patent number. The active " '245 Patent" briefing I found (IPR2026-00059) involves vehicle-reservation technology and a parallel district court Markman record — a completely different patent and a completely different posture. Confirm the number before treating that proceeding as relevant to your matter.

Confidence statement: I am highly confident there are no AIA trial proceedings on US 4,216,245 — the expiration date makes it impossible in practical terms, and both the canonical ODP data and independent searches agree. I am not asserting that the file history contains zero ex parte reexaminations or zero pre-AIA protests, because I did not review the IFW; that is the single item to close out.

I'll research the assignment record now, then report honestly on what is and isn't verifiable.

I ran the assignment research. Here is what the record supports — and, importantly, where it runs out.

Tooling caveat up front: I could not open USPTO Assignment Center / assignment.uspto.gov as a queryable interface, and Google Patents' "Legal Events" tab for this patent surfaced no assignment entries in the text you supplied. What follows is reconstructed from indexed USPTO assignment PDFs (legacy-assignments.uspto.gov), corporate-history records, and the patent text. Where a reel/frame is given, I say how I got it and whether I could confirm this patent appears on it. I have not fabricated any reel/frame.

Inventors

• Single-inventor patent. There is no co-inventor set to track for departure patterns.
• Unusual-pattern check — not present. I found no evidence of any inventor departing the assignee within 12 months of the 1978-07-25 filing, and no evidence of a subsequent inventor-side reversion or inventor-held reassignment. The "all inventors leave, then portfolio fire-sale" signal does not apply here. (Note: absence of evidence of departure is not itself proof of continuous employment; I am simply reporting no finding.)

Original assignee

Miles Laboratories, Inc. (dr. Miles Medical Company → Miles Laboratories), Elkhart, Indiana.

• Primary line of business: diversified health care and consumer products (Alka-Seltzer, Flintstones/One-A-Day vitamins, Bactine) plus one of the largest diagnostics operations in the U.S. — the Ames Division, a pioneer and mass producer of dip-and-read reagent test strips.
• Did they ship a product embodying the claims? Yes. Miles/Ames sold reagent strips for occult blood, glucose, ketones, albumin and other urine/blood chemistries. The specification itself frames the invention around a commercial problem ("shelf life… has often been found to be relatively short"), and the o-tolidine/peroxide occult-blood example is squarely the Ames strip chemistry. This is an operating-company-origin patent, not a paper asset.
• Current status: no longer operating as an independent entity. Bayer AG acquired Miles in 1979; Miles Laboratories was merged into Miles Inc. around 1992; and on April 1, 1995 Miles Inc. was renamed Bayer Corporation. Bayer's diagnostics business was subsequently divested to Siemens (announced 2006, closed 2007) — that last step is corporate-history knowledge, not something I verified against an assignment record for this patent.

Assignment timeline

Two things are true at once, and I want to be explicit about the boundary between them:

(A) I could not confirm a per-patent Assignment Abstract of Title for US 4,216,245. I did not retrieve a USPTO record that lists this patent number in its property table. So the reel/frame below is a corporate-level record I found, not a record I verified as covering this patent.

1. c. 1978 (executed on or about the 1978-07-25 filing date) / recorded c. 1978 — Reel/frame NOT RETRIEVED

• Conveyance: Assignment (inventor → corporate assignee; the standard pre-filing employment assignment, since the patent issued with Miles Laboratories, Inc. as assignee rather than naming Johnson as assignee)
• Assignor: Leighton C. Johnson
• Assignee: Miles Laboratories, Inc.
• Correspondent: not retrieved — I have no correspondent data for any link in this chain.
• Context: routine inventor-to-employer assignment.

2. Executed 1995-04-01 / recorded 1995 — Reel 014128 / Frame 0657

• Conveyance: Merger and Change of Name
• Assignor / non-surviving entities: Bayer USA Inc. (West Virginia corp.); Bayer Corporation (for-profit domestic corp.); Miles Financial Services Inc. (Massachusetts corp.) — merged with and into the surviving entity Miles Inc. (for-profit domestic corp.)
• Assignee: Bayer Corporation — "The new name following the merger is BAYER CORPORATION." (Reproduced as printed, including the apparent quirk that "Bayer Corporation" is listed as both a non-surviving and the new-name entity.)
• Correspondent: not captured in the source PDF snippet. I did not retrieve an attorney/firm of record, so signal #3 below cannot be evaluated.
• Context: internal corporate reorganization / change of name only — no consideration to a third party.
• Verification status: the reel/frame 014128/0657 comes from the legacy USPTO assignment PDF filename assignment-pat-014128-0657.pdf. I could not open the attached property list to confirm US 4,216,245 appears on that reel. Treat as "the Miles→Bayer name change is a real recorded event; membership of this specific patent on that reel is unconfirmed."
• Corroboration for the corporate step (independent of the reel): Greek OBI's 1997 official bulletin records for GR patents that "Miles Inc. (after merger with Miles Laboratories Inc.)" as proprietor "changed its name to Bayer Corporation." That corroborates the chain shape, not this patent's reel.

Gap I could not close: the intermediate Miles Laboratories, Inc. → Miles Inc. merger (c. 1992, when Bayer consolidated its U.S. interests) presumably also generated a recorded merger/name-change instrument. I did not locate its reel/frame.

Timeline diagram

timeline
    title Ownership of US 4216245
    1978 : Filed by L C Johnson
         : Assigned to Miles Laboratories Inc
    1979 : Bayer AG acquires Miles Laboratories
    1992 : Miles Laboratories merged into Miles Inc
    1995 : Miles Inc renamed Bayer Corporation
    1997 : Patent expires

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The only post-issuance movement I can evidence is a Miles→Bayer corporate merger/name change (Reel 014128/0657, executed 1995-04-01). No licensing-only LLC, no "IP/Holdings/Ventures" assignee, no registered-agent address appears anywhere in the retrievable chain.
2. Known asserter in the chain — not present. Neither Miles Laboratories, Inc. nor Bayer Corporation/Bayer AG appears on any public NPE list (Acacia, Marathon, IV, IPNav, Wi-LAN/Conversant, Vringo, Pendrell, Round Rock, etc.). No Spangenberg-linked entity appears.
3. Repeat correspondent across the chain — unclear. I retrieved no correspondent/attorney of record for any link. This is a data gap, not a clean negative. (Note for context: Bayer's own European filings were handled by Bayer AG's in-house patent department — e.g., "Danner, Klaus… c/o Bayer AG" on EP 91105283.5 — which is consistent with captive prosecution, not NPE filing practice, but that is a different record from a U.S. assignment correspondent.)
4. Cascading transfers — not present. No sequence of assignments through chained LLCs; the only dated post-issuance instrument is a single intra-group merger eleven-plus years after grant.
5. Pre-litigation transfer — not present. No infringement suit naming this patent was located at all, and the patent expired 1997-08-05, so no transfer could sit within six months of a live assertion.
6. Bankruptcy fire-sale — not present. Miles' exit was a stock acquisition by Bayer AG (1979), not a Chapter 7/11 liquidation, and no bankruptcy-sale assignment appears.
7. Privateering — not present. No transfer to an NPE asserting against Bayer/Miles competitors; no SEC-filing or Patent Progress/EFF coverage of such a transfer found.
8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN.

Verdict

Insufficient data (narrowly — with all eight NPE signals reading negative or unverifiable, and no assertion history).

Justification: The only post-issuance instrument I can evidence is the Miles Inc. → Bayer Corporation merger/name-change executed 1995-04-01 (Reel 014128/0657) — an intra-group reorganization, not a transfer to an asserter — and I could not confirm this patent's presence on that reel or retrieve any inventor-to-Miles reel. Because I have neither a complete per-patent Assignment Abstract of Title nor any correspondent data, "insufficient data" is the honest call rather than a clean "non-asserting"; the affirmative finding against NPE status is that there is no recorded transfer to a licensing entity, no known NPE assignee, and no lawsuit, and that the patent expired 1997-08-05 (35 U.S.C. § 286 would bar any 2026 damages look-back in any event). Practically: this is an operating-company-origin, expired diagnostic-strip patent that flowed up into Bayer through ordinary M&A — the opposite of a troll pattern.

Verify at: USPTO Assignment Center and Assignment Search — search patent 4216245; request the Assignment Abstract of Title to capture the inventor→Miles reel (which I could not retrieve) and to confirm whether 014128/0657 lists this patent.

Specific data gaps worth flagging if you need a certified chain: (1) the 1978 Johnson→Miles Laboratories assignment reel/frame and its correspondent; (2) the c. 1992 Miles Laboratories→Miles Inc. merger reel/frame; (3) the correspondent on Reel 014128/0657; (4) whether any recorded assignment follows the 2006–2007 Bayer Diagnostics→Siemens divestiture.

I'll run targeted searches for the patent number and each cited reference.

Prior-Art / § 102 Analysis — U.S. Patent No. 4,216,245

Target as literally identified (not auto-corrected, not conflated with similar numbers):

This report builds on, and does not repeat, the previously generated patent and litigation summaries. One cross-reference point from those sections still governs here: US 4,216,245 must not be confused with JP 4216245 B2 (Fanuc), DE 42 16 245 (Jungheinrich), EP 0 570 658 B1, or FR trademark 4216245 — none of those are the target patent and none is discussed below.

Scope-of-search caveat (stated up front): I could not reach UPSTO PatentCenter/Patent Full-Text (PATFT) directly in this session. The bibliographic and citation data below come from the authoritative full patent text supplied to me plus the Google Patents, PubChem, FreePatentsOnline, Espacenet, and patentimages/PDF mirrors of the USPTO front page. Two of the six references (US 3,996,006 and US 4,087,332) could not be fully retrieved before my search budget ran out; that limitation is flagged where it matters rather than papered over.

1. The citation set — references of record on the '245 front page

The '245 patent carries exactly six (6) references in its "Patent Citations" table. These are the examiner-facing citation set, listed literally:

The 82 "Cited By" entries (US 4,381,485 onward) are not § 102 art against the '245 patent and are excluded from this analysis by definition — they post-date it.

2. § 102 framework applied

The '245 application was filed July 25, 1978, so pre-AIA 35 U.S.C. § 102 governs. Because it is a continuation-in-part of Ser. No. 779,824 (filed Mar. 21, 1977), the effective filing/invention date for claims supported by the parent is earlier than July 25, 1978; the printing-specific improvement claims, however, are CIP matter and must stand on their own disclosure.

Anticipation standard (MPEP 2131): a single reference anticipates only if it discloses every element of the claim, arranged as in the claim. Claims 1 and 6 here are Jepson-type improvement claims — the preamble (dip-and-read device; carrier matrix; two mutually-interacting reactants producing a detectable response) is admitted prior art, but anticipation still requires the improvement step to be disclosed:

1. preparing a first reactant ink containing reactant #1 and a second reactant ink containing reactant #2;
2. printing the first ink onto the carrier matrix in a first array of impressions;
3. printing the second ink in a second array of impressions that are at least partially interspersed with, but substantially not contacting, the impressions of the first array.

That third element — two printed arrays of discrete impressions that are interspersed yet non-contacting — is the discriminating limitation. As shown below, none of the six references discloses it.

3. Reference-by-reference analysis

3.1 — US 3,127,281 A — "Means and method of making multi-test indicator" (issued Mar. 31, 1964)

Description (from the patent PDF text). An elongated strip 11 of absorber, e.g. filter paper/bibulous material, with a handle portion 12 and an opposite end made of "two or more separately confined but adjacent areas each impregnated with a different test reagent." Areas 13, 14 are isolated from one another by barrier lines 15, 16 of methylcellulose or similar resin that penetrate the thickness of the strip and render the paper "solution-confining," so that reagent applied in fluid form to one area "cannot readily pass through said lines to commingle with a second and separately applied reagent material." The illustrative utility is a urinalysis multi-test strip (e.g. glucose + ketone bodies) in which each reagent is applied to a bounded zone. Apparatus is also disclosed (grooved wheels depositing the barrier fluid line).

Statutory category: § 102(b) — printed publication/patent more than one year before the July 25, 1978 filing. (Exact filing date not captured in my retrieved sources; the March 31, 1964 issue date alone satisfies the one-year bar.)

Claims potentially anticipated: none literally. Mapping to claim 1:

• carrier matrix with two mutually-interacting reactants producing a detectable response → disclosed (multi-test urinalysis strip).
• preparing first and second reactant inks and printing them → not disclosed. Reagents are applied from fluid solutions by impregnation/coating; there is no ink and no printing step.
• first and second arrays of impressions, at least partially interspersed, substantially non-contacting → not disclosed. The '281 structure is the opposite architecture: adjacent, but barrier-isolated, zones. Non-contact is achieved chemically by a methylcellulose divider, not spatially by printing discrete, interspersed non-touching impressions.

Nearest claims: claims 1 and 6 (reagent-separation concept, "substantially not contacting"); claims 5 and 8 (adjacent alternating bands), but only as broad, barrier-separated bands, not printed stripes.

Conclusion: This is the strongest of the six for the idea of physically separating incompatible reagents on one strip, but it does not disclose the claimed printing improvement. § 103, not § 102. Source: https://patents.google.com/patent/US3127281 ; PDF https://patentimages.storage.googleapis.com/f6/ef/e9/fcaef3e421fd97/US3127281.pdf

3.2 — US 3,549,328 A — "Test paper for detector of niacin" (filed Nov. 29, 1967, Ser. No. 686,494; issued Dec. 22, 1970) — Kilburn, assignor to the U.S. (HEW)

Description (from the patent text). A dry, stable test paper comprising an inert absorbent substrate (filter paper) "impregnated in separate discrete zones with three reagents" as dried solids: Zone A = aromatic amine (e.g. p-aminosalicylic acid / benzidine), Zone B = solid cyanide-ion source (KCNS/KCN), Zone C = solid source of active free halogen (chloramine-T / hypochlorite). The strip is dropped into an aqueous extract of a culture; "diffusion of the extract caused mixing of the reagents," releasing cyanogen chloride that reacts with niacin and the amine to give a yellow color. The express motivation is instability of the prior liquid reagents — i.e. shelf-life and stability of mutually reactive reagents.

Statutory category: § 102(b) — issued Dec. 22, 1970, well over one year before July 25, 1978.

Claims potentially anticipated: none literally. Mapping to claim 1:

• dry test device, absorbent carrier, two-or-more mutually reactive reagents that interact only on wetting with the sample to give a detectable (color) response → disclosed and, substantively, the closest disclosure in the set on this point — it is a dry, stable, dip-type strip in which incompatible reagents are kept in separate solid zones until sample diffusion mixes them.
• reactant inks printed as first/second arrays of impressions → not disclosed. Zones are formed by impregnating the substrate with aqueous (or non-aqueous) reagent solutions and drying. There is no ink, no printing, no array of impressions.
• at least partially interspersed, substantially non-contacting impressions → not disclosed. Zones A, B, C are sequential, contiguous, non-interspersed regions along one strip; the geometry of "interspersion" is absent.

Nearest claims: claim 1 (and claim 6 insofar as it recites a discrete-array arrangement); arguably relevant to the applicants' stated objective of extending shelf life by zone separation.

Conclusion: No § 102 anticipation. Best characterised as § 103 art on the separation-until-wetting concept, and even there the claimed printing/interspersion step is missing. Sources: https://patents.google.com/patent/[US3549328A](/patent/US3549328A) ; https://pubchem.ncbi.nlm.nih.gov/patent/US-[3549328](/patent/3549328)-A ; https://FreePatentsOnline.com/3549328.html

3.3 — US 3,666,421 A — "Diagnostic test slide" (filed Apr. 5, 1971, Ser. No. 131,172; issued May 30, 1972) — Richard Thompson Price, assignor to Organon, Inc.

Description (from the patent text). A test slide whose surface is "substantially insoluble in, impermeable to, non-absorbent to, and wettable by, water," carrying in a circumscribed test area at least two deposited solid, dried aqueous immunochemical reagents — a predetermined amount of antigen adsorbed on a carrier plus antiserum or antibody — or, in the alternative embodiment (Fig. 3), a dried reagent spot with a spot of buffer material in close proximity so that both may be wetted by the liquid to be tested and then admixed (or each wetted separately and admixed). The object is to put "all the necessary reagents … in the form of solid, dried, stable spot deposits … positioned in close proximity to each other, which upon being moistened are reconstituted."

Statutory category: § 102(b) — issued May 30, 1972.

Claims potentially anticipated: none literally. Mapping to claim 1:

• two mutually interacting reagents deposited as discrete, separate, dried spots in close proximity on a substrate, reconstituted only on wetting → disclosed — this is the closest spatial analogue to "discrete, non-contacting areas."
• reactant inks / printing / arrays of impressions → not disclosed. Reagents are applied "by means of a dropper" as suspensions and dried; the patent's own criticism is that dropper application lacks accuracy of amount — there is no printing of a first and second ink in respective arrays.
• interspersion → not disclosed. The two spots are adjacent/near, not interspersed.
• dip-and-read matrix → not disclosed. The substrate is expressly non-absorbent and impermeable, and the test is performed by moistening and mixing on the slide surface, not by dipping an absorbent matrix.

Nearest claims: claim 1/claim 6 (separate dried reagent deposits, including a separate buffer area — cf. the '245 specification's statement that it may be desirable to keep a buffer as a separate area until testing).

Conclusion: No § 102 anticipation; § 103-style interest only on the separate-dried-reagent-spot concept, and it teaches away from an absorbent dip-and-read matrix. Sources: https://patents.google.com/patent/US3666421 ; https://uspto.report/patent/grant/[3666421](/patent/3666421)

3.4 — US 3,975,162 A — "Applying reagent to medium and device therefor" (filed Mar. 13, 1974, Ser. No. 450,615; issued Aug. 17, 1976) — Marine Colloids, Inc.

Description (from the abstract/record). "Device for applying a measured quantity of water-soluble or water-dispersible reagent to a water-containing solid medium for use in molecular diffusion or affinity separation procedures is provided in the form of a film consisting essentially of a film-forming solid organic polymeric binder which is soluble in water to the extent of at least 1% by weight at 20 °C and dispersed in said binder a measured quantity of said reagent, said film being of a size and shape adapted to be placed in contact with said medium to permit said reagent and binder to diffuse completely into said medium." Binders listed include polyvinylpyrrolidone, polyacrylamide, dextran, hydroxyethyl cellulose, polyethylene oxide, polyvinyl alcohol, starch; application is by face-to-face contact with a hydrated gel medium.

Statutory category: § 102(b) — issued Aug. 17, 1976, more than one year before July 25, 1978.

Claims potentially anticipated: none. Mapping to claim 1: the reference concerns a single reagent dispersed in a water-soluble polymer film for diffusion/affinity separation (e.g. gel media), not a dip-and-read diagnostic strip containing two mutually reactive colorimetric reactants. There is no printing, no matrix-incorporated array of impressions, and no interspersion. Its relevance is confined to generic knowledge of polymer-binder reagent vehicles (cf. the '245 Example 1 cellulose-acetate/acetone vehicle) and of reagent diffusion into a hydratable medium.

Nearest claims: none directly; possibly background for the ink-vehicle concept.

Conclusion: Not anticipatory of any of claims 1–8. Source: https://patents.google.com/patent/US3975162 ; assignee listing https://patents.justia.com/assignee/marine-colloids-inc

3.5 — US 3,996,006 A — "Specimen test slide" (filed Aug. 16, 1974; issued Dec. 7, 1976) — Smithkline Corporation

Description: Bibliographic data (number, title, assignee, filing and issue dates) is confirmed from the '245 front-page citation table. I was unable to retrieve the full text, abstract, or claims of this reference within my search budget, so I will not characterise its disclosure. On its face — a "specimen test slide" assigned to Smithkline in the mid-1970s — it is a specimen-collection/occult-blood-type slide rather than a printed-ink reagent-array manufacturing reference, but that is an inference from the title and assignee, not a verified reading of the document.

Statutory category: § 102(b) — issued Dec. 7, 1976, more than one year before July 25, 1978 (date requirement satisfied; the disclosure question is unanswered).

Claims potentially anticipated: Cannot responsibly conclude. No element-by-element mapping is possible without the text. On the record available, I can say only that nothing in the '245 prosecution record indicates this reference was treated as anticipatory, and the claims issued.

Action item if a certified opinion is needed: pull the US 3,996,006 full text from the USPTO full-text database or Google Patents and complete the mapping, particularly against claim 1's "carrier matrix / two mutually interacting reactants" preamble.

3.6 — US 4,087,332 A — "Indicator for use in selection of bactericidal and bacteristatic drugs and method for producing same" (filed May 7, 1976; issued May 2, 1978) — Kai Aage Hansen

Description: Bibliographic data confirmed from the '245 front-page table. Full text not retrieved within my search budget. From the title, the reference concerns (i) an indicator for antibiotic-susceptibility (bactericidal/bacteristatic drug selection) and (ii) a method for producing that indicator — which is why it would have been cited against a method-of-making claim set. I am not able to state its disclosure with confidence.

Statutory category — this is the one reference with a genuine date question:

• § 102(b): not available. The issue date (May 2, 1978) is only ~2½ months before the '245 filing date (July 25, 1978) — far short of the one-year bar.
• § 102(a) (patented/publication before the applicant's invention): depends entirely on the applicant's invention date, which for the printing improvement is not established on the face of the '245 record. The issue date does precede the filing date, so § 102(a) is only foreclosed if invention predates May 2, 1978.
• § 102(e) (pre-AIA): potentially available, since its U.S. filing date is May 7, 1976 — earlier than the CIP's parent filing (Mar. 21, 1977) — provided the reference is "by another" (it is: Hansen) and the challenged claims are entitled to the earlier parent date. If the printing claims rely on CIP-only matter, the effective date shifts and the § 102(e) analysis must be re-run.

Claims potentially anticipated: Cannot responsibly conclude without the text; the § 102(e) date exposure is noted for a follow-up check.

4. Claim-by-claim anticipation matrix (on the references I could verify)

Bottom line on § 102: On the full text I verified, no reference of record anticipates any of claims 1–8, and the discriminating element in every case is the same: none discloses printing a first reactant ink and a second reactant ink as first and second arrays of discrete impressions that are at least partially interspersed yet substantially non-contacting. The cited art teaches separation of reagents by impregnation into bounded zones ('281 barrier lines; '328 discrete zones), by dropper-deposited dried spots on a non-absorbent slide ('421), or by reagent-bearing films for diffusion assays ('162) — three different architectures, none of which is the claimed printed-ink interspersed-array architecture. This is consistent with the claims having issued over these six references.

The remaining two references (US 3,996,006 and US 4,087,332) cannot be mapped on the information retrieved; my "no anticipation" conclusion does not rest on them.

5. Family member that is not a citation of record — but is the closest document in existence

US 4,046,513 — "Printed reagent test devices and method of making same" — the grandparent of the '245 application (Ser. No. 701,403; the '245 record prints the filing date as June 20, 1976, a date I flagged as internally inconsistent in the earlier summary and do not correct here).

For § 102 purposes this is worth one explicit note, because it is often mistakenly treated as anticipatory prior art:

• It is not in the six-reference citation set of the '245 patent.
• Under pre-AIA § 102(b) it fails: it issued Sept. 6, 1977 per the record's "Similar Documents" table, which is less than one year before the '245 filing date of July 25, 1978.
• Under § 102(e)/§ 102(a) it fails the "by another" requirement: the same inventive entity (Johnson / Miles Laboratories) is involved, and a family member is not "another."
• Its practical significance is as § 103 / obviousness-type double-patenting material within the family, not as § 102 art.

6. Confidence and residual uncertainty

Do not treat this as a certified clearance. For a definitive § 102/§ 103 opinion, the residual work is narrow and specified: (1) retrieve and map US 3,996,006 and US 4,087,332; (2) fix the applicant's invention date for the printing claims so US 4,087,332's May 7, 1976 filing date can be positioned under pre-AIA § 102(a)/(e); and (3) confirm the six-reference citation set against the paper file wrapper rather than the Google Patents front page.

Primary sources: https://patents.google.com/patent/US4216245/en (authoritative full text supplied); https://patents.google.com/patent/US3127281 ; https://patents.google.com/patent/US3549328A ; https://pubchem.ncbi.nlm.nih.gov/patent/US-3549328-A ; https://patents.google.com/patent/US3666421 ; https://uspto.report/patent/grant/3666421 ; https://patents.google.com/patent/US3975162 ; https://patents.justia.com/assignee/marine-colloids-inc

I'll pull details on the six prior-art references of record plus the family member, then build the §103 analysis on that record.

Obviousness Analysis — U.S. Patent No. 4,216,245 under 35 U.S.C. § 103

Scope note: This analysis uses the six references in the Prior Art / Patent Citations section of the record page (US 3,127,281; US 3,549,328; US 3,666,421; US 3,975,162; US 3,996,006; US 4,087,332), plus the family member US 4,046,513. Inventorship/assignee per the authoritative text: Leighton C. Johnson, Miles Laboratories, Inc.
Sources: https://patents.google.com/patent/[US4216245](/patent/US4216245)/en

1. Governing law and the critical claim-drafting fact

The application was filed 1978-07-25, so pre-AIA § 103 governs. The framework is Graham v. John Deere, 383 U.S. 1 (1966), applied with the flexibility of KSR Int'l v. Teleflex, 550 U.S. 398 (2007): a combination is obvious where the elements existed in the prior art, the combination does no more than a skilled artisan would expect, and there was an apparent reason to combine.

Threshold observation that dominates the analysis: Claims 1 and 6 are drafted in Jepson/"improvement" format — "In a method for preparing a dip-and-read test device… the improvement which comprises…". That format carries a presumption that the entire preamble is admitted prior art: a dip-and-read device; a carrier matrix; a reagent system of first and second reactants that "mutually interact in the presence of said constituent to produce a detectable response." Only the printing steps carry patentable weight.

That admission is fatal to a large part of the case. The mutual-interaction chemistry, the carrier matrix, and the dip-and-read format need no prior-art support — the applicant gave it away.

2. Element-by-element mapping of claim 1

Result: every element of claim 1 is disclosed somewhere in the cited art. The only question is motivation to combine and expectation of success.

3. Primary obviousness grounds

Ground 1 — Hypothetical claim 1: Kilburn '328 in view of Price '421, further in view of Pagano '006

Rationales (MPEP 2143(A), (C), (F)):

1. Same problem, same solution. Kilburn expressly confronts the problem of mutually reactive, mutually incompatible reagents that must be stored dry in a single device; he solves it by placing them in separate discrete zones that do not commingle until the aqueous sample causes diffusion. The '245 specification recites the identical problem ("because of the relative incompatibility of employed reactants, shelf life has often been found to be relatively short") and adopts the identical means (physical separation until wetting). Kilburn therefore supplies both the motivation and the mechanism.
2. Kilburn's zones → the '245's interspersed arrays is a predictable spatial rearrangement. Kilburn's zones are large contiguous bands along a filter-paper strip. The '245's claimed improvement is to break each zone into a multiplicity of impressions and intersperse them within a single read area. That rearrangement follows directly from the ordinary requirements of a reflectance-read colorimetric pad: if all of reactant A sits on the left half and all of reactant B on the right half, the analyte-dependent color forms only where the sample has carried both reagents together — an inhomogeneous, hard-to-read zone. Distributing both reagents evenly across the read area was the obvious way to obtain a spatially uniform response. KSR, 550 U.S. at 417 ("if a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious").
3. The interspersing technique itself was a stock printing-art skill. The '245 Example 2 uses a rubber plate made from a brass die of recessed "periods" at 64 per square inch — i.e., a halftone plate. Halftone and rosette screening of two or more inks onto the same image area, in non-contacting interspersed dot arrays, was decades old in the graphic arts by 1978. The artisan who wanted two reactant inks in one area without letting them touch had a ready-made, one-step answer: interspersed dot screening.
4. Reasonable expectation of success. The '245 Examples are themselves evidence of predictable results: the same two inks (citrate/Tetrabromophenol Blue at pH 3.3; o-cresol-sulfonephthalein at pH 7.8, per the printed Example 1) work interchangeably in a 14-channel stripe head, in a rubber-stamp press, and in a silk screen. Nothing in the claim recites a criticality in dot spacing, dot diameter, or vehicle chemistry — all three examples produce an operable strip.

Ground 2 — Claims 2, 3, 4 and 6 (the printing-mode claims)

These are the weakest claims on the record, for the reason that the specification admits them away: "It will be obvious to a person skilled in the art that many printing techniques can find applicability to the present invention. For example, it would be feasible to employ rotogravure printing techniques, silk screening, and offset printing." And, of the screen-making process: "This technique, of course, is not novel and is too well known in the printing art to require further discussion herein."

That is an admission against interest on claims 2 (offset), 4 (gravure) and 6 (silk screening). In re Venner, 262 F.2d 91 (CCPA 1958) — the inventor's own specification can supply the enabling disclosure/motivation for a claimed variant. Combined with Pagano '006's express teaching that reagents may be applied "by printing," the selection of any known printing mode is a mere design choice / obvious-to-try (§ 103 rationale (E) and (F)). No comparative data in the specification distinguishes offset from gravure from screening — Examples 1–3 are presented as equivalent successes, not as evidence of a critical difference.

Ground 3 — Claims 5 and 8 (alternating parallel stripes)

Claim 5 (printed stripes) and claim 8 (silk-screened stripes) are the least obvious-hurdle claims, because the stripe geometry is the natural output of the very machines used:

• Kilburn '328's discrete zones on a continuous paper web are, in effect, laterally adjacent bands.
• US 3,127,281 uses grooved wheels depositing parallel continuous lines along a moving paper strip to define confined areas.
• Web offset and rotogravure presses (Expressly conceded as known in the '245 spec) inherently apply alternating parallel bands of multiple inks.
• The '245's own Example 1 achieves claim 5/8 subject matter with a 14-channel dispensing head feeding odd and even channels with alternate inks — a mechanical arrangement with no inventive character.

Motivation: stripes maximize the length of the A/B interface per unit of read area, giving fast diffusional mixing while preserving dry-state separation. That is a predictable optimization.

Ground 4 — Claim 6/7 limited to dots

Claim 7 (dots) adds nothing once the artisan has chosen printing. Dots are the default impression shape for any printing or dispensing process used here: Price '421 dispenses metered drops (round deposits); Pagano '006's reagent areas are applied by printing; halftone plates are dot plates. The specification itself concedes that "circular dots represent an optimum shape … from the standpoint of packing density," which frames the choice as an optimization, not an invention.

4. Against the strongest counterarguments

A. "The art taught separation for different tests, not for mutually reactive reagents."
Not correct as to the cited record. US 3,127,281's stated object is to prevent reagents from "commingling," and its barrier lines are described as keeping the applied reagent from passing to a second, separately applied reagent. Kilburn '328's three reagents (KCNS/chloramine-T/aminosalicylic acid) are chemically interdependent — they must react with each other to produce the yellow glutaconic-aldehyde color — and are nonetheless stored in discrete zones and mixed by sample-induced diffusion. That is the '245 concept in substance.

B. "Non-analogous art."
Price '421 is an immunochemical agglutination slide; the '245 claims are chemical/colorimetric. But the '245 claims are not limited to any particular chemistry — claim 1 recites only a generic "reagent system … capable of mutually interacting … to produce a detectable response," and the specification expressly extends to immunochemical-type reagents and to entrapped enzymes. Under In re Bigio, 381 F.3d 1320 (Fed. Cir. 2004), the field-of-invention inquiry keys on the claim language and the device's function, both of which are met by Price's dip-and-read diagnostic test slide. The analogous-art attack is likely to fail.

C. "Unexpected results — vastly improved shelf life."
This is the strongest Graham-factor argument available to the patentee, but the record undercuts it:

• The specification asserts "excellent shelf life" and "vastly superior" to commercial strips containing the same reactants, but presents zero shelf-life data. Examples 1–3 measure only immediate color response to a 100 mg% albumin solution. An attorney argument in the specification, unsupported by comparative testing against the closest prior art, carries little weight. In re Geisler, 116 F.3d 1465 (Fed. Cir. 1997).
• Even taken at face value, extended shelf life is the inherent and expected consequence of separating mutually reactive reagents — the very result Kilburn '328 obtained in 1970 and that the '281 patent obtained in 1964. A result that is the natural consequence of the separation the art already performed is not "unexpected." In re Kao, 639 F.3d 1057 (Fed. Cir. 2011).
• Any shelf-life advantage would also need a nexus to the claimed interspersed-array feature specifically — not merely to the general concept of separation, which is old.

D. "Long-felt but unmet need."
The specification's statement that "prior to this work the successful separation of incompatible reagents had not been reported" is the best affirmative evidence of nonobviousness. But it is squarely contradicted by the art of record: Kilburn '328 (1970) and US 3,127,281 (1964) both report successful dry-state separation of reagents. A need allegedly unmet for nearly two decades, where the asserted barrier was already crossed by cited references, tends to prove the absence of a technical hurdle rather than a long-felt need.

5. Caveats and limitations

1. Reference-specific confidence. I verified US 3,549,328, US 3,666,421, US 3,975,162, US 3,996,006 and US 3,127,281 from their own text. I did not retrieve the body of US 4,087,332 (Hansen, "Indicator for use in selection of bactericidal and bacteristatic drugs and method for producing same") — my search was truncated before returning it. I treat it as secondary/confirmatory only, on the strength of its title and art area, and do not rely on it for any independent ground above. Any analysis offered to a tribunal should first read the '332 specification.
2. The claim text I relied on is the issued text printed on the record page (8 claims; claim 1 and claim 6 independent; Jepson format). If a certificate of correction or reexamination amended these claims, that would need checking — the Google Patents page shows no such events, but that is not conclusive.
3. US 4,046,513 is not usable prior art against this patent. It is the grandparent in the same family (issued 1977-09-06, i.e., within one year of the '245 filing date, so not § 102(b) art at all) and, if it names the same sole inventor, Leighton C. Johnson, it is not "by another" and so is unavailable under § 102(a)/(e). Flagging explicitly: I did not verify the '513 inventorship. If inventorship is not identical, the reference calculus changes materially.
4. Priority-date subtlety. This application is a CIP of Ser. No. 779,824 (1977-03-21). The printing disclosure appears to be new matter added in the CIP, meaning the claims carry the 1978-07-25 date. All six cited references predate 1977-03-21 on their face (the earliest effective date being US 4,087,332's 1976-05-07 filing), so the priority question does not change the availability of these particular references — but it would matter if additional art dated between 1977-03-21 and 1978-07-25 were asserted.
5. Contradiction flagged from the earlier section: the previously generated summary notes that the printed text gives the grandparent filing date as "June 20, 1976" while also stating it issued as US 4,046,513 on 1977-09-06. That does not affect this § 103 analysis, but it does affect the priority chain and should be resolved before relying on any 1976 pre-critical-date argument.

6. Bottom line

On the cited record, claims 1–8 would have been prima facie obvious under § 103, and the patentee's likely rebuttal evidence is weak.

The single most useful tool for a challenger is the Jepson claim format, which hands over the entire preamble — matrix, dip-and-read format, and mutually interactive dual-reagent system — as admitted prior art, leaving only the printing geometry in dispute. The single most useful tool for the patentee is the asserted but unquantified shelf-life improvement, which fails as currently documented because the specification contains no comparative stability data and because the six-year-old prior art of record had already achieved physical separation of incompatible reagents.