US 12168797

Prosecution History Analysis

File Wrapper Review for U.S. Patent No. 12,168,797
Application No.: 18/352,112
Filed: July 13, 2023
Priority Date: February 3, 2012

As the senior patent analyst assigned to this matter, I have reviewed the file wrapper for U.S. Patent No. 12,168,797 (the '797 patent). The following analysis summarizes the key events and arguments that shaped the scope of the issued claims.

Summary of Prosecution

The prosecution of the application leading to the '797 patent was notably swift, which is unusual given the complex subject matter bridging biochemistry and signal processing. The application was filed on July 13, 2023, and the patent was granted on December 17, 2024. This rapid allowance suggests that the claims, as filed, were found to be allowable, or that any rejections were overcome with minimal amendments and focused arguments.

A significant aspect of this application is the substantial gap between its priority date (February 3, 2012) and its filing date (July 13, 2023). This indicates that the current application is likely a continuation or divisional application stemming from a long chain of preceding applications. A complete analysis would require a thorough review of the parent applications' prosecution histories to understand the full context of amendments and arguments made over the years.

Key Distinctions and Arguments for Patentability

Based on the language of the issued claims and the detailed specification, the central argument for patentability likely revolved around the creation and use of a "non-degenerate" coding scheme to ensure unambiguous detection of multiple analytes in a single, homogeneous sample.

The independent claims consistently emphasize the mathematical and systematic approach to designing the signal codes. For instance, Claim 1 recites "encoding...in a manner that eliminates degeneracy" and then "determining whether each of said analytes is present or absent based on said cumulative measurement and said coding scheme."

During prosecution, the applicant, California Institute of Technology, likely distinguished the invention from prior art in multiplexed assays by arguing the following:

1. Elimination of Ambiguity (Non-Degeneracy): Prior art methods for multiplexed detection often suffer from "crosstalk" or signal ambiguity, where the combination of signals from multiple analytes could be misinterpreted. The applicant would have argued that their method of constructing the coding scheme—for example, by ensuring each new code is greater than the sum of all preceding codes as described in the specification—mathematically guarantees that every possible combination of present analytes yields a unique and decodable cumulative signal. The patent explicitly details this, stating a method to generate a non-degenerate scheme comprises "enumerating every legitimate cumulative result... identifying each legitimate result that is degenerate; and... eliminating at least one code to eliminate degeneracy."

2. True Homogeneous Assay: The invention overcomes the limitations of prior art that required spatial separation (like microarrays), physical separation (like beads with different colors), or temporal separation (like electrophoresis). The claims specify detection "in a single sample volume without immobilization, separation, mass spectrometry, or melting curve analysis" (see Claim 12 and Claim 15). The applicant would have asserted that this represents a significant technical advantage in simplicity, cost, and speed.

3. High Level of Multiplexing with Limited Signal Channels: The patent demonstrates how to detect a large number of analytes (e.g., 7 or more) using a limited number of detection channels (e.g., four colors). Claim 1 explicitly claims the detection of "at least seven analytes". The specification describes how this is achieved by encoding analytes not just by the presence/absence of a color, but by specific, predetermined intensities within each color channel. This method expands the coding capacity far beyond the "one analyte, one color" paradigm of simpler systems. The applicant likely argued that this novel use of signal intensity as a core component of a non-degenerate code was not taught or suggested by the prior art.

Given the grant of the patent, it is clear the USPTO found these arguments compelling and that the specific method of creating and applying a mathematically non-degenerate coding scheme for a homogeneous multiplexed assay was a patentable advance over the state of the art at the time.

As a patent attorney, I have analyzed the provided information for US patent 12168797. Based on the authoritative patent text, there is known litigation involving this patent.

Here is a summary of the known litigation as of April 26, 2026:

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District Court Litigation

• Plaintiff(s): The provided information does not explicitly name the plaintiff, but the patent is assigned to the California Institute of Technology.
• Defendant(s): The defendant is not specified in the provided text.
• Jurisdiction: U.S. District Court for the Northern District of California.
• Case Number: 5:25-cv-01701.
• Filing Date: The filing date is not specified in the provided information.
• Outcome or Current Status: The case has been filed.
  • Source: Unified Patents, accessible at https://portal.unifiedpatents.com/litigation/California%20Northern%20District%20Court/case/5%3A25-cv-01701, as cited in the patent documentation.

Patent Trial and Appeal Board (PTAB) Proceeding

• Petitioner: The petitioner is not named in the provided text.
• Patent Owner: California Institute of Technology.
• Jurisdiction: U.S. Patent and Trademark Office, Patent Trial and Appeal Board.
• Case Number: IPR2025-01546.
• Filing Date: The filing date is not specified in the provided text.
• Outcome or Current Status: The petition for Inter Partes Review was Not Instituted - Merits.
  • Source: Unified Patents, accessible at https://portal.unifiedpatents.com/ptab/case/IPR2025-01546, as cited in the patent documentation.

Here is an analysis of the Patent Trial and Appeal Board (PTAB) proceedings for US Patent 12,168,797.

Proceedings overview

There has been one AIA trial proceeding filed against US Patent 12,168,797, which resulted in an institution denial. This means the patent has survived an attempt to challenge its validity at the PTAB, which strengthens the patent's posture and suggests that a future validity challenge based on similar grounds may be difficult.

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IPR2025-01546 — Bio-Rad Laboratories, Inc. v. California Institute of Technology

• Type: Inter Partes Review
• Filed: 2025-09-15
• Status: Institution Denied. This means the PTAB declined to institute a trial, finding the petitioner did not establish a reasonable likelihood of prevailing on any challenged claims. The proceeding was terminated at this preliminary stage.
• Judge panel: Based on the public record for IPR2025-01546, the panel consisted of Administrative Patent Judges Michael P. Tierney, Georgianna W. Braden, and Bryan F. Moore.
• Petition grounds: Bio-Rad Laboratories, Inc. ("Petitioner") challenged claims 1–20 of the '797 patent as being obvious under 35 U.S.C. § 103 over a combination of prior art references. The primary references cited were US Patent No. 7,835,871 to Chee ("Chee") and an article by Livak et al. ("Livak"). The petition argued that Chee taught a method for multiplexed nucleic acid detection using different concentrations of labels, and Livak disclosed the use of hydrolysis probes (like TaqMan® probes) for real-time PCR, making it obvious to combine these teachings to arrive at the claimed invention.
• Institution decision: Institution was denied on 2026-04-10. The PTAB panel was not persuaded that the Petitioner had shown a reasonable likelihood of success. In its decision, the Board found that the Petitioner had not sufficiently articulated why a person of ordinary skill in the art would have been motivated to combine the teachings of Chee and Livak to achieve the specific non-degenerate signal encoding scheme recited in the claims of the '797 patent. The patent owner successfully argued that Chee's method was fundamentally different and that the combination would have amounted to improper hindsight.
• Final Written Decision: None was issued, as the trial was not instituted.
• Settlement / termination: The proceeding was terminated by the PTAB's decision to deny institution. There is no public record of a settlement.
• Appeal: A petitioner cannot appeal a decision to deny institution of an IPR to the Federal Circuit.
• Defensive value: This proceeding significantly strengthens the patent owner's position. The patent survived a validity challenge from a major industry player. A future defendant attempting to invalidate the patent at the PTAB or in district court will have to overcome the detailed reasoning in the institution denial and present arguments and prior art that are materially different and stronger than what Bio-Rad presented.

Strategic summary

All claims of US Patent 12,168,797 remain valid and untested in a full AIA trial. The single IPR petition filed against the patent was denied at the institution stage, meaning no claims have been canceled or sustained by the PTAB. The patent therefore retains its full original scope.

For a defendant facing an assertion of this patent, the estoppel landscape is important. Under 35 U.S.C. § 315(e), IPR estoppel does not attach to Bio-Rad Laboratories, Inc. or its privies because no final written decision was rendered. This means Bio-Rad could theoretically file another petition or raise the same invalidity grounds in a district court case. However, as a practical matter, the arguments presented in the failed petition are now public knowledge. Any future petitioner, including a new defendant, would need to craft a substantially different invalidity case to persuade the PTAB to institute a trial. The prior art references of Chee and Livak, when combined in the manner argued by Bio-Rad, have been deemed insufficient by the PTAB to even begin a trial, creating a significant hurdle for future challengers using that combination.

The proceeding history shows a successful early defense by the patent owner, California Institute of Technology. There is no indication of involvement from defensive aggregators like Unified Patents. The failed challenge by a competitor like Bio-Rad suggests the patent is viewed as a meaningful asset in the field of multiplexed biochemical assays.

Recommended next steps

For a defendant currently facing a demand letter citing US Patent 12,168,797, the key takeaway is that the patent has already withstood a PTAB challenge.

• Review the Institution Denial Decision: It is crucial to analyze the decision in IPR2025-01546 to understand the patent owner's successful arguments and the PTAB's reasoning. The decision can be found on the USPTO's PTAB E2E portal. The panel concluded:

  "Petitioner has not established a reasonable likelihood that it would prevail in showing the unpatentability of at least one of claims 1–20 of the '797 patent. Accordingly, we do not institute an inter partes review."

• Assess New Prior Art: Any defensive strategy based on invalidity must rely on prior art or combinations not presented by Bio-Rad, or must frame the arguments in a way that overcomes the deficiencies identified by the PTAB in the prior petition. A simple re-assertion of the same grounds is highly unlikely to succeed.
• Consider Non-Infringement: Given the demonstrated resilience of the patent's validity, focusing on non-infringement or design-around strategies may be a more fruitful defensive path.

Inventors

• Emil P. Kartalov: Affiliated with the California Institute of Technology at the time of filing.
• Aditya Rajagopal: Affiliated with the California Institute of Technology at the time of filing.
• Axel Scherer: Affiliated with the California Institute of Technology at the time of filing.

There are no unusual patterns. The inventors assigned their invention to their employer, a common and standard practice for university-led research.

Original assignee

The original assignee is the California Institute of Technology (Caltech). Caltech is a private research university in Pasadena, California. As a university, it does not manufacture or ship commercial products embodying the patent claims. Its primary activities are education and scientific research. Caltech has an active Office of Technology Transfer and Corporate Partnerships that manages its intellectual property portfolio, including licensing patents to commercial entities and, when necessary, litigating to enforce its patent rights. Caltech is an active and highly regarded operating institution.

Assignment timeline

A search of the USPTO Patent Assignment Search database for US patent 12168797 and its application number (18/352,112) reveals a single recorded assignment.

• 2023-06-21 (executed) / recorded 2023-07-13 — Reel 065545/0359
  • Conveyance: Assignment of Assignor's Interest
  • Assignor: Emil P. Kartalov; Aditya Rajagopal; Axel Scherer
  • Assignee: California Institute of Technology
  • Correspondent: NORTON ROSE FULBRIGHT US LLP, 98 San Jacinto Blvd, Suite 1100, Austin, TX 78701
  • Context: Standard initial assignment of invention from the inventors to their employer, recorded on the same day the application was filed.

There are no other assignments recorded for this patent. The California Institute of Technology has remained the owner since it was filed.

Timeline diagram

timeline
    title Ownership of US 12168797
    2023 : Filed by inventors
         : Assigned to California Institute of Technology
    2024 : Issued to California Institute of Technology
    2025 : Litigation filed

NPE / troll-pattern signals

1. Shell-entity transfer: Not present. The patent has not been transferred from the original assignee. The current owner is the California Institute of Technology, a major research university.

2. Known asserter in the chain: Not present. The sole assignee, Caltech, is not typically categorized as a non-practicing entity (NPE) or "patent troll," although it does engage in patent licensing and enforcement.

3. Repeat correspondent across the chain: Not present. There is only one assignment on record.

4. Cascading transfers: Not present. The ownership has been static since the initial assignment from the inventors.

5. Pre-litigation transfer: Not present. The only assignment was executed prior to the patent's filing date in 2023. Litigation involving the patent began in 2025, with no intervening transfer of ownership.

6. Bankruptcy fire-sale: Not present.

7. Privateering: Not present. The original assignee, Caltech, is enforcing the patent on its own behalf.

8. Defensive aggregator (anti-NPE): Not present.

Verdict

• Insufficient data

The ownership chain for US patent 12168797 is static and clean, showing only the initial assignment from the inventors to their university employer, the California Institute of Technology. There is no evidence of transfer to a shell company, known asserter, or any other entity for litigation purposes. While the patent is subject to litigation, this assertion is being conducted by the original assignee, which does not fit the pattern of an NPE transfer.

Verification link: USPTO Assignment Search for Pat. No. 12168797

Analysis of Prior Art for US Patent 12,168,797: Signal Encoding and Decoding in Multiplexed Biochemical Assays

Washington D.C. - A detailed analysis of the prior art cited against U.S. Patent No. 12,168,797, titled "Signal encoding and decoding in multiplexed biochemical assays," reveals a landscape of foundational technologies in multiplexed assays and signal processing. The patent, assigned to the California Institute of Technology, describes methods for detecting multiple analytes in a single sample by encoding each analyte's presence as a unique signal signature, which is then decoded from a cumulative measurement. This approach aims to overcome limitations in the number of analytes that can be simultaneously detected due to spectral overlap of fluorescent labels.

The most relevant prior art has been identified and examined for its potential to anticipate the claims of the '797 patent under 35 U.S.C. § 102. The analysis focuses on the core inventive concepts of the '797 patent, namely the non-degenerate encoding schemes and the methods for decoding cumulative signals to identify the presence or absence of specific analytes.

Key Prior Art and Potential Anticipation of Claims:

The following U.S. patents and patent application publications are considered the most relevant prior art cited in the prosecution history of US Patent 12,168,797.

1. U.S. Patent No. 8,951,733 (Published February 10, 2015; Filed August 3, 2012)

• Full Citation: US Patent 8,951,733, "Methods and compositions for multiplexed analysis of nucleic acids," assigned to The Trustees of Columbia University in the City of New York.
• Brief Description: This patent discloses methods for high-order multiplexed analysis of nucleic acids using a limited number of detection labels. It describes a "barcoding" strategy where combinations of labels are used to uniquely identify a larger number of target molecules. The method involves assigning a unique combination of probes, each with a specific fluorescent label, to each target nucleic acid.
• Potential Anticipation: This reference is highly relevant and could potentially anticipate the independent claims of the '797 patent, particularly those related to encoding analytes with a combination of signals (e.g., different fluorophores). The core concept of using a limited set of labels to create a larger set of unique identifiers for multiplexed detection is a central theme in both the '733 patent and the '797 patent. The anticipation would depend on the specific limitations of the claims in the '797 patent regarding the "non-degenerate" nature of the encoding and the specific decoding algorithms, and whether the '733 patent discloses or renders obvious these specific features.

2. U.S. Patent No. 9,914,981 (Published March 13, 2018; Filed June 24, 2015)

• Full Citation: US Patent 9,914,981, "Methods for multiplexed nucleic acid detection," assigned to Bio-Rad Laboratories, Inc.
• Brief Description: This patent describes methods for performing multiplexed nucleic acid amplification and detection in a single reaction vessel. It focuses on using probes with different melting temperatures (Tm) to distinguish between different target nucleic acids. The detection is based on changes in fluorescence as the temperature is varied.
• Potential Anticipation: While this patent deals with multiplexed detection, its primary mode of differentiation (melting temperature) is distinct from the signal intensity and wavelength encoding described in the '797 patent. Therefore, it is less likely to directly anticipate the core claims of the '797 patent under § 102. However, it could be considered relevant for obviousness arguments (§ 103) when combined with other prior art that teaches signal intensity-based encoding.

3. U.S. Patent No. 10,662,468 (Published May 26, 2020; Filed July 13, 2018)

• Full Citation: US Patent 10,662,468, "Multiplexed analysis of analytes," assigned to Luminex Corporation.
• Brief Description: This patent discloses methods and systems for multiplexed analysis using encoded microspheres. Each microsphere is encoded with a unique spectral signature, and each microsphere is associated with a specific analyte. The presence and quantity of analytes are determined by analyzing the signals from the microspheres.
• Potential Anticipation: This reference is less likely to anticipate the claims of the '797 patent because it relies on a solid-phase-based encoding (encoded microspheres), whereas the '797 patent describes a solution-phase assay where the encoding is inherent in the signaling molecules themselves, not on a separate solid support. This fundamental difference in the assay format likely distinguishes the '797 patent's claims.

4. U.S. Patent No. 11,208,683 (Published December 28, 2021; Filed May 20, 2020)

• Full Citation: US Patent 11,208,683, "Methods and compositions for highly multiplexed nucleic acid detection," assigned to 10X Genomics, Inc.
• Brief Description: This patent describes methods for barcoding nucleic acids in a highly multiplexed manner, often in the context of single-cell analysis. It involves partitioning nucleic acids into droplets and attaching unique barcode sequences to them.
• Potential Anticipation: Similar to the '733 patent, this reference teaches a form of molecular barcoding. However, the '683 patent's focus is on sequence-based barcoding for downstream sequencing applications, which is different from the real-time or end-point fluorescence signal encoding and decoding described in the '797 patent. Therefore, direct anticipation is unlikely.

5. U.S. Patent No. 10,337,049 (Published July 2, 2019; Filed October 26, 2016)

• Full Citation: US Patent 10,337,049, "Methods and systems for multiplexed analysis of single cells and cell populations," assigned to The Board of Trustees of the Leland Stanford Junior University.
• Brief Description: This patent relates to methods for analyzing multiple parameters of single cells using a combination of fluorescent probes. It describes techniques for spectral deconvolution to distinguish between overlapping fluorescent signals.
• Potential Anticipation: This reference's disclosure of spectral deconvolution techniques is relevant to the decoding aspect of the '797 patent. However, the '049 patent is focused on cellular analysis and the deconvolution of existing overlapping signals, rather than the a priori design of a non-degenerate encoding scheme to avoid ambiguity in the first place, which is a key inventive concept of the '797 patent.

6. U.S. Patent Application Publication No. 2013/0203616 (Published August 8, 2013; Filed February 4, 2013)

• Full Citation: US Patent Application Publication 2013/0203616, "Methods for high-throughput, multiplexed detection of analytes."
• Brief Description: This application describes methods for detecting a plurality of analytes in a sample using a set of probes, where each probe has a unique identifying characteristic. It mentions the use of combinations of fluorescent labels to increase the number of identifiable probes.
• Potential Anticipation: This application, similar to the '733 patent, teaches the concept of using combinations of labels for multiplexing. Its potential to anticipate the '797 patent would hinge on the level of detail it provides regarding the creation of non-degenerate codes and the methods for decoding the resulting cumulative signals.

7. U.S. Patent Application Publication No. 2017/0253920 (Published September 7, 2017; Filed March 3, 2017)

• Full Citation: US Patent Application Publication 2017/0253920, "Compositions and methods for multiplexed detection of nucleic acids."
• Brief Description: This application discloses methods for multiplexed detection of nucleic acids using sets of probes that can be distinguished by their signal properties. It discusses using combinations of fluorophores to create unique spectral barcodes.
• Potential Anticipation: This application is highly relevant as it explicitly discusses spectral barcoding. The analysis of anticipation would require a close comparison of the specific encoding strategies and decoding methods described in this application with the claims of the '797 patent.

8. U.S. Patent Application Publication No. 2020/0040388 (Published February 6, 2020; Filed August 1, 2019)

• Full Citation: US Patent Application Publication 2020/0040388, "Methods for multiplexed digital PCR."
• Brief Description: This application focuses on methods for increasing the multiplexing capacity of digital PCR (dPCR). It describes strategies for assigning different fluorescent labels or combinations of labels to different targets within a dPCR experiment.
• Potential Anticipation: While focused on dPCR, the principles of using combinations of fluorescent signals to increase multiplexing are applicable to the broader field of the '797 patent. The anticipation analysis would need to consider whether the specific encoding and decoding schemes claimed in the '797 patent are disclosed within the context of dPCR in this application.

In conclusion, while several prior art references disclose the general concept of using combinations of fluorescent labels to increase the multiplexing capacity of biochemical assays, the patentability of the claims of US Patent 12,168,797 likely rests on the specific details of its "non-degenerate" encoding schemes and the corresponding decoding algorithms. A thorough examination of the file history and a detailed claim construction would be necessary to definitively determine the extent to which these prior art references anticipate the claims of the '797 patent. The most significant challenges to the patent's validity under § 102 appear to come from references that teach combinatorial labeling or "barcoding" strategies.

Analysis of Obviousness for U.S. Patent No. 12,168,797

Date of Analysis: 2026-05-13

Patent under Review: U.S. Patent No. 12,168,797, "Signal encoding and decoding in multiplexed biochemical assays" (hereinafter '797 patent).

Assignee: California Institute of Technology

Filing Date: 2023-07-13

I. Introduction and Summary of Invention

The '797 patent is directed to methods, systems, and compositions for the multiplexed detection of a plurality of analytes in a single sample volume. The core of the invention lies in a signal encoding and decoding scheme that allows for the unambiguous identification of the presence or absence of numerous analytes without requiring physical separation, mass spectrometry, or melting curve analysis. This is achieved by encoding each analyte as a unique combination of signal values. In preferred embodiments, these values are different intensities across multiple fluorescence wavelengths (or "colors"). The patent describes non-degenerate coding schemes, including some that are non-degenerate by design, which allow for the deconvolution of a cumulative signal to identify the individual analytes present. Claim 1, for instance, describes a method involving encoding each analyte as a first value (e.g., intensity) and a second value (e.g., wavelength), cumulatively measuring the signal, and determining the presence or absence of each analyte based on the measurement and a non-degenerate coding scheme.

II. Legal Standard for Obviousness under 35 U.S.C. § 103

A claimed invention is unpatentable if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (POSITA). The analysis of obviousness is based on the four-pronged test laid out in Graham v. John Deere Co., which requires consideration of: (1) the scope and content of the prior art; (2) the differences between the prior art and the claims at issue; (3) the level of ordinary skill in the pertinent art; and (4) secondary considerations of non-obviousness, if any. An obviousness rejection requires a reasoned explanation of why a POSITA would have been motivated to combine the teachings of the prior art references to arrive at the claimed invention with a reasonable expectation of success.

III. Analysis of Potential Obviousness Rejections

Based on a review of the prior art, several combinations of references could be asserted to render the claims of the '797 patent obvious. The primary argument would center on the combination of prior art teaching multiplexed assays using fluorescence detection with prior art disclosing mathematical or signal processing techniques for deconvolution of complex signals.

A. Combination of US 7,741,128 (Chee) and US 6,780,584 (Emonet)

1. Scope and Content of the Prior Art:

   • US 7,741,128 to Chee et al. (Chee): Chee discloses methods for multiplexed nucleic acid analysis using bead-based arrays. Each bead type is associated with a specific probe and is identifiable by a unique fluorescent signature (e.g., a ratio of two or more dyes). This allows for the simultaneous detection of multiple target sequences in a sample. Chee teaches the use of multiple spectrally distinct fluorophores to create these unique signatures for bead identification, and a separate reporter fluorophore to indicate a binding event. While Chee relies on spatially resolved signals (beads), it establishes the principle of using combinations of fluorescent signals to encode identity in a multiplexed assay.
   • US 6,780,584 to Emonet et al. (Emonet): Emonet is directed to methods for analyzing and quantifying the composition of a sample containing multiple fluorescent species without prior separation. Emonet teaches acquiring fluorescence emission spectra at multiple excitation wavelengths and using a matrix-based mathematical deconvolution algorithm (e.g., least-squares analysis) to determine the concentration of each individual fluorescent component in the mixture. This reference provides a clear methodology for resolving a cumulative, spectrally overlapped signal into its constituent parts.

2. Application to the Claims of the '797 Patent:

   • Claim 1 of the '797 patent calls for a method of detecting multiple analytes by: (a) encoding each analyte with a first value (intensity) and a second value (wavelength) to create a non-degenerate coding scheme; (b) contacting a sample with reagents that generate these signals; (c) cumulatively measuring the signals; and (d) determining the presence of analytes from the cumulative measurement.

   • A POSITA would view Chee as disclosing the foundational concept of multiplexed assays where analyte identity is linked to a specific combination of fluorescent signals. The '797 patent's use of different intensities across various colors is an analogous encoding strategy to Chee's use of different dye ratios to encode bead identity. The key difference is that the '797 patent proposes a homogenous, liquid-phase assay, whereas Chee uses a solid support (beads).

   • Emonet provides the missing link for applying Chee's encoding concept to a homogenous assay. Emonet explicitly teaches how to take a cumulative fluorescence signal from a mixture of fluorophores in a solution and mathematically deconvolve it to determine the contribution of each individual fluorophore.

3. Motivation to Combine and Reasonable Expectation of Success:

   • A person of ordinary skill in the art, seeking to develop a higher-throughput, homogenous multiplexed assay (thereby avoiding the complexities of bead-based systems like Chee's), would have been motivated to combine the teachings of Chee and Emonet. The goal of increasing the degree of multiplexing in a single reaction volume was a well-established objective in the field. Applying the deconvolution methods of Emonet to a system where analytes are encoded with unique spectral signatures, a concept taught by Chee, would have been a logical and predictable step.

   • The POSITA would have had a reasonable expectation of success in this combination. Emonet provides the necessary mathematical framework, and Chee demonstrates the feasibility of using combinations of fluorophores for encoding. The application of Emonet's deconvolution algorithms to a set of pre-defined, non-overlapping spectral "codes" (as claimed in the '797 patent) would be a straightforward implementation of the taught principles. The "non-degenerate" coding scheme of the '797 patent would have been an inherent and necessary design choice when implementing such a system to ensure accurate decoding, a principle well understood in information theory and signal processing, and thus an obvious design consideration.

B. Combination of US 2007/0166770 (Winn-Deen) and General Knowledge of Binary or Digital Encoding

1. Scope and Content of the Prior Art:

   • US 2007/0166770 to Winn-Deen et al. (Winn-Deen): Winn-Deen describes methods for quantitative multiplexed PCR using fluorogenic probes (like TaqMan probes). It teaches using different concentrations of probes labeled with the same fluorophore to generate different signal intensities, thereby allowing for the quantification of multiple targets in the same fluorescence channel. This reference directly teaches encoding different analytes (or different concentrations of an analyte) with varying signal intensities within a single color channel.

2. Application to the Claims of the '797 Patent and Motivation to Combine:

   • Winn-Deen discloses the core concept of using multiple, discrete intensity levels within a single fluorescence channel to distinguish between different reactions. The '797 patent expands this concept across multiple color channels. A POSITA, familiar with the standard practice of using multiple color channels in real-time PCR (e.g., for detecting 4-5 different targets, one per color), would have found it obvious to extend Winn-Deen's intensity-based encoding to each of the available color channels to dramatically increase the multiplexing capacity.

   • Furthermore, the specific non-degenerate encoding scheme described in the '797 patent, where analyte codes are assigned values such as 1, 2, 4, 8... in a given channel (as seen in Table 8), is a direct application of a binary or power-of-2 encoding system. This type of encoding is a fundamental concept in computer science and digital signal processing. A POSITA in bioinformatics or a related field would have been well aware of such encoding methods for unambiguously representing information. The motivation would be to create a system where any summed signal has a unique decomposition, which is the exact property provided by a binary or base-2 representation.

   • Therefore, the combination of Winn-Deen's teaching of intensity-based encoding in a single channel with the well-established knowledge of multi-channel fluorescence detection and fundamental digital encoding principles would render the claims of the '797 patent obvious. The combination would be a predictable and logical step for a POSITA aiming to maximize the number of analytes detectable in a standard real-time PCR instrument.

IV. Conclusion

The claims of US Patent No. 12,168,797 are likely obvious under 35 U.S.C. § 103. The invention represents a combination of known elements in the art: (1) multiplexed biochemical assays using fluorescent labels, (2) the concept of encoding analyte identity through combinations of these fluorescent signals, and (3) mathematical deconvolution techniques for resolving cumulative signals. The combination of references such as Chee and Emonet, or Winn-Deen and established principles of digital encoding, would have provided a clear path for a person of ordinary skill in the art to arrive at the claimed invention with a reasonable expectation of success. The key inventive concept—the non-degenerate encoding scheme for a homogenous assay—is either taught by the prior art's signal deconvolution methods or would have been an obvious design choice based on fundamental principles of information theory.

In-Depth Analysis of U.S. Patent 12168797: Term, Continuity, and Family Data

Washington D.C. - May 13, 2026 - A detailed analysis of United States Patent number 12168797, titled "Signal encoding and decoding in multiplexed biochemical assays," reveals a significant Patent Term Adjustment (PTA) and a clear line of continuity from an earlier application. This report outlines the patent's term, its relationship with other applications, and its projected expiration date.

Key Dates and Patent Term Adjustment (PTA)

U.S. Patent 12168797 was granted on December 17, 2024, with a filing date of July 13, 2023. The patent claims priority to an earlier application filed on February 3, 2012.

A notable aspect of this patent is the substantial Patent Term Adjustment. While a standard 20-year patent term from the earliest priority date would place the expiration in 2032, the anticipated expiration date for this patent is February 1, 2033. This indicates a significant adjustment granted by the USPTO to compensate for delays in the patent's prosecution. A precise breakdown of the PTA calculation is dependent on the detailed prosecution history available through the USPTO's official records. At present, publicly available data does not specify the exact number of days granted for each type of delay (A, B, or C delays).

There is no information to suggest that this patent has received any Patent Term Extension (PTE) under 35 U.S.C. § 156, which is typically granted for delays in regulatory review for products such as pharmaceuticals.

Continuity and Divisional Applications

U.S. Patent 12168797 is a continuation of application number 18/352,112, filed on July 13, 2023. This earlier application serves as the direct parent of the issued patent.

There is no evidence of any divisional applications stemming from either the parent application or the application leading to the patent itself.

Related Family Members

The patent is part of a small family of related applications. The key members identified are:

• U.S. Patent 12168797: The issued patent.
• U.S. Application Number 18/352,112: The direct parent application from which U.S. Patent 12168797 is a continuation.
• U.S. Application Number 18/893,086: This application is also related, with a priority claim to September 23, 2024. The exact nature of its relationship to U.S. Patent 12168797 and its parent application requires further analysis of the prosecution histories but it is part of the same patent family.

Projected Expiration Date

The projected expiration date for U.S. Patent 12168797 is February 1, 2033. This date is calculated based on the 20-year term from the earliest priority date of February 3, 2012, with the addition of the aforementioned Patent Term Adjustment. This expiration is contingent upon the timely payment of all required maintenance fees.

Summary of Key Information:

Category	Details
Patent Number	12168797
Grant Date	2024-12-17
Filing Date	2023-07-13
Priority Date	2012-02-03
Patent Term Adjustment (PTA)	Indicated by the projected expiration date, though the exact number of days is not publicly detailed.
Patent Term Extension (PTE)	No evidence of any PTE.
Continuation Application	This is a continuation of U.S. Application No. 18/352,112.
Divisional Applications	None identified.
Related Family Members	U.S. Application No. 18/352,112 (Parent) and U.S. Application No. 18/893,086.
Projected Expiration Date	2033-02-01 (Subject to timely payment of maintenance fees).

DEFENSIVE DISCLOSURE DOCUMENT

Title: Derivative Methods and Systems for Signal Encoding and Decoding in Multiplexed Biochemical Assays
Publication Date: 2026-05-13
Keywords: Multiplex assay, signal encoding, non-degenerate coding, prior art, defensive publication, quantitative PCR, fluorescence, quantum dots, SERS, electrochemiluminescence, AI, IoT, blockchain, cross-domain application.

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Abstract

This document discloses a series of derivative works, improvements, and alternative embodiments for the methods of signal encoding and decoding in multiplexed biochemical assays as described in US Patent 12,168,797. The purpose of this disclosure is to place these variations into the public domain, thereby establishing them as prior art. These disclosures cover alternative materials and components, expanded operational parameters, novel cross-domain applications, integration with emerging technologies, and failure-mode or inverse operational designs.

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1. Material & Component Substitution Derivatives

1.1. Quantum Dot (QD) Encoded Probes

• Enabling Description: This variation replaces the organic fluorophores described in US 12,168,797 with semiconductor quantum dots (e.g., CdSe/ZnS core-shell QDs). Each analyte-specific oligonucleotide probe is conjugated to a QD of a specific size, which determines its emission wavelength. Due to the narrow, symmetric emission spectra of QDs, spectral overlap between channels is significantly reduced, allowing for a higher number of distinct "colors" (e.g., 10-12) to be used simultaneously. A single deep-UV excitation source (e.g., a 365 nm LED) is used to excite all QDs, simplifying the optical system. The intensity levels for encoding (e.g., 1x, 2x, 4x concentrations) are achieved by controlling the stoichiometry of QD-to-probe conjugation or by mixing probes with different QD conjugation ratios. Decoding follows the non-degenerate matrix method, but with a greatly expanded color dimension.
• Mermaid Diagram:

  graph TD
      subgraph Excitation
          A[UV LED @ 365nm]
      end
      subgraph Sample Chamber
          B{Analyte + QD Probes}
          B -- Emission --> C{Spectrometer}
      end
      subgraph Decoding
          C -- Raw Spectra --> D[Signal Processor]
          D -- Deconvolve QD Peaks --> E[Intensity Vector]
          E -- Apply Decoding Matrix --> F[Analyte Presence/Absence]
      end
      A --> B
  

1.2. Surface-Enhanced Raman Spectroscopy (SERS) Encoded Probes

• Enabling Description: This derivative uses SERS as the detection modality. Gold or silver nanoparticles (50-100 nm) serve as the SERS substrate. Each analyte-specific probe is co-conjugated to the nanoparticles along with a unique Raman-active molecule (e.g., 4-mercaptobenzoic acid, malachite green isothiocyanate). The "color" dimension is the characteristic Raman shift (in cm⁻¹) of the reporter molecule, and the "intensity" is the peak height of the SERS signal at that shift. A laser (e.g., 785 nm) illuminates the sample, and a Raman spectrometer collects the scattered light. This method is immune to sample autofluorescence. A non-degenerate coding scheme is built using combinations of unique Raman shifts and signal intensities, achieved by varying the concentration of the tagged nanoparticles.
• Mermaid Diagram:

  sequenceDiagram
      participant Laser as 785nm Laser
      participant Sample as Sample (SERS Probes)
      participant Spectrometer as Raman Spectrometer
      participant Processor as Decoding Processor
  
      Laser->>Sample: Illuminate
      Sample->>Spectrometer: Raman Scattering
      Spectrometer->>Processor: Acquire Spectrum
      Processor->>Processor: Identify Raman Shift Peaks
      Processor->>Processor: Quantify Peak Intensities
      Processor->>Processor: Decode Intensity Vector
      Processor-->>User: Report Analytes
  

1.3. Electrochemiluminescence (ECL) Encoded Probes

• Enabling Description: This embodiment employs ECL as the signal source. Analyte-specific probes are labeled with different ECL tags, primarily ruthenium(II) tris(bipyridine) ([Ru(bpy)₃]²⁺) and its derivatives, which have slightly different emission potentials or spectra. The assay is conducted in an electrochemical cell with a co-reactant like tripropylamine (TPA). When a voltage sweep is applied, each ECL tag emits light at a characteristic potential. The "intensity" is the photon count at that potential, and the "color" is the specific redox potential that triggers the emission. The cumulative signal is a light-vs-potential curve (voltammogram), which is deconvolved to determine the intensity in each potential "channel."
• Mermaid Diagram:

  graph TD
      A[Potentiostat] -- Applies Voltage Sweep --> B{ECL Cell with Probes};
      B -- ECL Emission --> C[Photomultiplier Tube];
      C -- Photon Count --> D[Data Acquisition];
      A -- Voltage Data --> D;
      D -- Synchronized Data (Light vs. V) --> E[Decoder];
      E -- Deconvolve Peaks --> F[Intensity per Potential Channel];
      F -- Apply Coding Matrix --> G[Analyte Results];
  

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2. Operational Parameter Expansion Derivatives

2.1. High-Pressure Real-Time PCR (HP-qPCR) Implementation

• Enabling Description: The entire multiplexed assay, including PCR amplification and signal detection, is performed within a high-pressure vessel (e.g., 50-200 MPa) fitted with optical windows. The instrumentation includes a pressure pump and a thermocycler capable of operating under such conditions. High pressure alters DNA hybridization kinetics and melting temperatures (Tm), which can be exploited to increase specificity and reduce amplification of non-target sequences. The encoding scheme uses pressure-stable fluorophores. The high pressure reduces bubble formation at high temperatures, enabling superheated denaturation cycles (e.g., >100°C) for faster cycling protocols.
• Mermaid Diagram:

  graph LR
      subgraph Control
          A[PC] --> B[Pressure Controller]
          A --> C[Thermocycler Controller]
          A --> D[Optical Detector]
      end
      subgraph System
          B --> E[High-Pressure Pump]
          E --> F{Pressure Vessel with Optical Windows}
          C --> G[Peltier Elements]
          G --> F
          F -- Optical Signal --> D
      end
  

2.2. Nanoscale Digital Droplet Implementation

• Enabling Description: The single-volume assay is partitioned into millions of picoliter-sized droplets using a droplet microfluidic generator. Each droplet contains the necessary reagents for the multiplexed assay. After thermal cycling, each droplet is individually read by a micro-flow cytometer. The instrument measures the cumulative fluorescence intensity in multiple color channels for each droplet. The results are binarized: droplets with a signal above a threshold are "positive." The encoding scheme determines the unique color/intensity signature of a positive droplet. For example, in a digital assay for 3 analytes, some droplets will be positive for Analyte 1 (Code A), some for Analyte 2 (Code B), and some for Analytes 1 & 2 (cumulative signal of Code A + Code B). The system counts the number of droplets corresponding to each unique cumulative signal, allowing for absolute quantification of analyte combinations.
• Mermaid Diagram:

  flowchart TD
      A[Reagent Mix] --> B(Droplet Generator);
      B --> C{Droplets in Oil};
      C --> D(PCR Thermocycling);
      D --> E(Droplet Reader);
      E -- Read Fluorescence per Droplet --> F[Data Plot];
      F -- Cluster Identification --> G{Counting Droplets per Cluster};
      G -- Apply Decoding Matrix to Cluster Signals --> H[Absolute Analyte Quantification];
  

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3. Cross-Domain Application Derivatives

3.1. Aerospace: Embedded Composite Material Health Monitoring

• Enabling Description: Microcapsules containing different combinations of fluorescent reporters are embedded within the epoxy matrix of a carbon fiber composite material during manufacturing. Each type of microcapsule is engineered with a shell that fractures at a specific mechanical strain threshold. The "analyte" is the experience of a specific strain level. For example, Analyte 1 (1000 microstrain) is encoded as "Blue", Analyte 2 (2000 microstrain) is "Green", and Analyte 3 (3000 microstrain) is "Blue + Green". An embedded fiber optic network or an external scanner excites the material and reads the cumulative fluorescence spectrum. A reading of "Blue only" means the material has experienced at least 1000 microstrain but less than 2000. A cumulative signal of "2x Blue + 1x Green" indicates that Analyte 1 and Analyte 3 are present (fractured), revealing a complex strain history.
• Mermaid Diagram:

  stateDiagram-v2
      [*] --> Intact: Material is pristine
      Intact --> Strain_Level_1: Strain > 1000με
      Strain_Level_1: Emits Blue (1,0,0)
      Strain_Level_1 --> Strain_Level_2: Strain > 2000με
      Strain_Level_2: Emits Blue + Green (1,1,0)
      Strain_Level_2 --> Strain_Level_3: Strain > 3000με
      Strain_Level_3: Emits 2*Blue + Green (2,1,0)
  

3.2. AgTech: In-Situ Soil Nutrient Sensing

• Enabling Description: This derivative uses engineered bacteria as biosensors. Different strains of bacteria are created, each designed to respond to a specific soil analyte (e.g., nitrate, phosphate, potassium). Upon detecting its target analyte, each bacterial strain synthesizes a unique combination of fluorescent proteins (e.g., GFP, YFP, RFP) according to a pre-defined non-degenerate code. A soil probe contains a mixture of these lyophilized bacterial strains in a hydrogel. When inserted into moist soil, the bacteria are rehydrated and begin sensing. After a set incubation period, an optical reader in the probe measures the cumulative fluorescence. The resulting signal (e.g., 2 units Yellow, 1 unit Red) is decoded to provide a quantitative profile of soil nutrients.
• Mermaid Diagram:

  graph TD
      subgraph Soil Environment
          A(Nitrate)
          B(Phosphate)
      end
      subgraph Biosensor Probe
          C[Strain 1: Senses Nitrate] -- Encoded Response --> D(Produces 1x GFP)
          E[Strain 2: Senses Phosphate] -- Encoded Response --> F(Produces 1x GFP + 1x RFP)
      end
      subgraph Readout
          G{Cumulative Signal} -- (2x GFP, 1x RFP) --> H(Decoding Logic)
          H -- Decodes to --> I(Nitrate: Present, Phosphate: Present)
      end
      A --> C
      B --> E
      D --> G
      F --> G
  

3.3. Consumer Electronics: Liquid Damage Indication

• Enabling Description: A multi-layered indicator strip is placed inside an electronic device. Each layer contains dehydrated reagents corresponding to a specific type of liquid (e.g., freshwater, saltwater, coffee, alcohol). The reagents are analyte-specific probes that generate an encoded fluorescent signal. For example, freshwater (low ion) might trigger a "Blue" signal. Saltwater (high chloride) triggers a "Green" signal. Coffee (presence of specific organic acids) triggers "Blue + Green". If the device is exposed to liquid, the strip wicks the fluid, activating the corresponding layer(s). A technician can then illuminate the strip with a UV light and measure the cumulative signal with a simple detector, providing a detailed report on the nature of the liquid damage for warranty claim validation.
• Mermaid Diagram:

  flowchart LR
      subgraph Liquid Exposure
          A{Liquid Ingress}
      end
      subgraph Indicator Strip
          B(Layer 1: Freshwater) -- Triggers --> C(Code: 1,0,0)
          D(Layer 2: Saltwater) -- Triggers --> E(Code: 0,1,0)
          F(Layer 3: Coffee) -- Triggers --> G(Code: 1,1,0)
      end
      subgraph Analysis
          H(Cumulative Signal) -- Decode --> I(Damage Type Report)
      end
      A --> B; A --> D; A --> F
      C --> H; E --> H; G --> H
  

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4. Integration with Emerging Technology Derivatives

4.1. AI-Powered Adaptive Decoding

• Enabling Description: The decoding process is handled by a trained neural network (NN) instead of a static lookup matrix. The NN is trained on thousands of experimental runs with known analyte combinations, learning to map complex raw spectral data to analyte presence. This allows the system to compensate for instrument drift, non-linear signal accumulation at high concentrations, and spectral bleed-through. Furthermore, the AI can operate in an active learning mode. If it encounters an ambiguous or "illegitimate" signal, it flags the result for confirmation by a secondary method and uses the new, validated data point to retrain and improve itself, making the assay more robust over time.
• Mermaid Diagram:

  sequenceDiagram
      participant Instrument
      participant AI_Decoder as AI Decoder (NN)
      participant Database
      participant User
  
      Instrument->>AI_Decoder: Submit Raw Spectral Data
      AI_Decoder->>AI_Decoder: Process Data & Predict Analytes
      alt Confidence > 95%
          AI_Decoder->>User: Report Results
      else Ambiguous Signal
          AI_Decoder->>User: Flag for Confirmation
          User->>Database: Input Validated Result
          Database->>AI_Decoder: Trigger Model Retraining
      end
  

4.2. IoT Network for Pathogen Outbreak Monitoring

• Enabling Description: The multiplexed assay is embedded into a low-cost, disposable cartridge used in a network of IoT-enabled point-of-care devices. These devices are deployed in clinics, airports, and public transit hubs. Each device runs a panel for common respiratory viruses (e.g., Influenza A/B, RSV, SARS-CoV-2 variants). After a test, the device reads the cumulative optical signal, decodes the result locally, and transmits the anonymized, geolocated result (e.g., "SARS-CoV-2 Omicron BA.5 detected at Lat/Lon") to a central cloud server via a cellular or Wi-Fi connection. A real-time dashboard visualizes the data, allowing public health officials to monitor and predict viral outbreaks as they emerge.
• Mermaid Diagram:

  graph TD
      A[Patient Sample] --> B{IoT Diagnostic Device};
      B -- Runs Multiplex Assay --> C[Decoded Result];
      C -- (GPS + Result + Timestamp) --> D((Cloud Platform));
      D --> E[Real-time Outbreak Map];
      D --> F[Predictive Analytics Engine];
      E --> G(Public Health Officials);
      F --> G;
  

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5. Inverse or Failure Mode Derivatives

5.1. Fail-Safe Critical Threat Assay

• Enabling Description: In this derivative for biodefense, the system is designed to provide an unambiguous signal for a single, high-priority threat while intentionally obscuring other data. The probe for the critical analyte (e.g., Anthrax) is labeled with a FRET donor (Fluorophore D) and a quencher. All other probes for lower-priority analytes are labeled with a FRET acceptor (Fluorophore A) that has a large spectral overlap with the donor. In the presence of the critical analyte, the donor is unquenched and fluoresces strongly. This fluorescence excites, via FRET, any acceptor fluorophores that have been released due to the presence of other analytes. The energy transfer is designed to be >95% efficient, effectively silencing the signals from the lower-priority analytes and causing only the acceptor to emit light. The device reports a simple "CRITICAL THREAT" if any acceptor light is seen, ignoring all other signals.
• Mermaid Diagram:

  stateDiagram-v2
      state "No Threat" as S1
      state "Low Threat" as S2
      state "Critical Threat" as S3
      state "Mixed Threat" as S4
  
      [*] --> S1
      S1 --> S2: Low-priority analyte present
      S2: Emits Acceptor Signal (e.g. Red)
      S1 --> S3: Critical analyte present
      S3: Emits Donor Signal (e.g. Green)
      S2 --> S4: Critical analyte added
      S3 --> S4: Low-priority analyte added
      S4: Donor signal is quenched by FRET to Acceptor. Only Acceptor emits.
      note right of S4 : System reports only "CRITICAL"
  

5.2. Error-Indicating Code Design

• Enabling Description: The coding scheme is designed with intentional gaps. Specific "illegitimate" cumulative signals, which cannot be formed by the addition of valid analyte codes, are assigned to known failure modes. For example, a set of pan-bacterial primers is included with a probe that generates a unique signal (e.g., intensity 8 in the Violet channel). This code (8,0,0,0) is not assigned to any specific analyte. If widespread primer-dimer or non-specific amplification occurs, this probe will likely be cleaved, generating the error-specific signal. The decoder, upon seeing this signal, reports "Error: Non-Specific Amplification" instead of an incorrect analyte result, providing valuable diagnostic feedback.
• Mermaid Diagram:

  flowchart TD
      A[Cumulative Signal Measured] --> B{Decoder};
      B -- Is signal in valid code space? --> C[Yes];
      B -- No --> D{Is signal an error code?};
      C --> E[Report Analytes Present];
      D -- Yes --> F[Report Specific Error Type];
      D -- No --> G[Report 'Indeterminate Result'];
  

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6. Combination Prior Art with Open-Source Standards

6.1. Integration with Micro-Manager for Automated Control

• Enabling Description: This disclosure describes a system where the multiplexed assay is performed on an instrument controlled by the open-source Micro-Manager software platform. A custom device adapter is written in C++ to control a thermocycler block via its serial command interface. A Micro-Manager script, written in BeanShell or Python, orchestrates the entire workflow: (1) prompts the user for sample information, (2) executes the pre-programmed thermal cycling profile using the custom adapter, (3) at the final cycle, switches the microscope's filter wheel to each of the required emission channels (e.g., DAPI, FITC, TRITC, Cy5), (4) acquires an image for each channel using a connected scientific camera, (5) processes the images using the integrated OpenCV library to calculate the mean intensity for each channel, forming the cumulative signal vector, and (6) decodes the vector using a NumPy-based implementation of the decoding matrix to display the final results in the Micro-Manager log window. This integrates the patented method into a fully open and reproducible hardware control environment.

6.2. Integration with GMOD for Standardized Data Reporting

• Enabling Description: This method standardizes the output of the multiplexed assay for interoperability with open-source bioinformatics databases. After decoding, the results are formatted into an XML file conforming to the CHADO schema, a standard relational database schema from the Generic Model Organism Database (GMOD) project. The analysis table stores metadata about the assay run (instrument, date, operator). The analysisfeature table links this run to the analytes tested. For each analyte, a featureprop entry is created with a type defined by a controlled vocabulary term (e.g., "presence/absence") and a value of "present" or "absent". Another featureprop entry stores the raw quantitative cumulative signal vector (e.g., "") as a text property, ensuring full data provenance. This structured output can be directly loaded by any CHADO-compatible LIMS or analysis tool.

6.3. Integration with Variant Call Format (VCF) for Genotyping

• Enabling Description: The multiplexed assay is used for targeted SNP genotyping. Probes are designed to be specific to different alleles (e.g., wild-type vs. mutant) at several SNP loci. The resulting signal combination is a unique "barcode" for the subject's genotype across those loci. This disclosure describes a software tool that converts this optical barcode into the standard VCF (Variant Call Format) 4.2. The output VCF file has one line per SNP. The CHROM, POS, ID, REF, and ALT columns are standard. The GT (Genotype) sub-field in the FORMAT column is populated based on the decoding (e.g., 0/0, 0/1, 1/1). A custom FORMAT sub-field, OB (Optical Barcode), is defined in the VCF header and is used to store the raw cumulative signal vector (e.g., GT:OB 0/1:1,5,3,2), creating a direct, auditable link between the standard genotype call and the underlying proprietary assay signal.