Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status of the Claims
Claims 1-4, 8, 10, 12, 14, 19, 21, 22, 28, 33, and 35 are pending and examined herein.
Priority
This application, filed 02/23/2023, claims benefit of PRO 63/313,697, filed 02/24/2022. This benefit is acknowledged and the claims examined herein are treated as having an effective filing date of 02/24/2022.
Withdrawn Rejections/Objections
The rejection of claims 1, 3, and 14 under 35 U.S.C. 112(b) has been withdrawn in response to Applicant’s amendment.
Amended Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-4, 8, 10, 12, 19, 21-22, 28, 33, and 35 are rejected under 35 U.S.C. 103 as being unpatentable over Otieno et al., “On-line protein capture on magnetic beads for ultrasensitive microfluidic immunoassays of cancer biomarkers” Biosensors and Bioelectronics (published 10/08/2013, referred to herein as Otieno) in view of Li et al., “AC Electrothermal Flow-Enhanced, Label-Free Immunosensor for Rapid Electrochemical Sensing” Proceedings of the 15th Annual IEEE International Conference (published 09/27/2020, IDS dated 03/08/2024, referred to herein as Li) and Wei et al., “Homogeneous electrogenerated chemiluminescence immunoassay for the detection of biomarkers by magnetic preconcentration on a magnetic electrode” Analytical and Bioanalytical Chemistry (published 05/06/2019, referred to herein as Wei) as evidenced by Krause et al., “Rapid Microfluidic Immunoassays of Cancer Biomarker Proteins Using Disposable Inkjet-Printed Gold Nanoparticle Arrays” ChemistryOPEN (published 08/2013, referred to herein as Krause) and Centi et al., “A disposable immunomagnetic electrochemical sensor based on functionalised magnetic beads and carbon-based screen-printed electrodes (SPCEs) for the detection of polychlorinated biphenyls (PCBs)” Analytica Chimica Acta (published 03/12/2005, referred to herein as Centi).
Regarding claim 1, Otieno teaches a microfluidic method for detecting a target protein (p. 269, col. 1, para. 4, lines 2-7) comprising contacting the sample with dual-labelled magnetic beads conjugated to a capture antibody and an HRP reporter enzyme in a microfluidic chip (p. 270, col. 1, para. 6, line 3 – col. 2, para. 1, line 1), mixing the sample and beads (p. 270, col. 2, para. 1, lines 1-5), performing immunomagnetic enrichment with a magnet (p. 271, col. 2, para. 2, lines 4-10), and detecting the target protein by measuring levels of the reporter (p. 272, col. 1, para. 1, lines 1-4). Otieno teaches an immunosensor with a working electrode, a counter electrode, and a reference electrode (Figure 1B).
Regarding claim 2, Otieno teaches that the capture antibody is monoclonal (p. 269, col. 2, para. 2, lines 13-15).
Regarding claim 3, Otieno teaches a sample to bead volume ratio of 5:40, or 1:8. However, it would have been prima facie obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to perform routine optimization of the components in the claimed invention to make and use the claimed invention. As noted in In re Aller, 105 USPQ 233 at 235, more particularly, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. Routine optimization is not considered inventive and no evidence has been presented that arriving at the claimed sample to bead ratio was anything other than routine, that the properties of the ratio from the optimization has any unexpected properties, or that the results should be considered unexpected in any way as compared to the closest prior art. Optimization of parameters is a routine practice that would be obvious for the artisan to employ. See MPEP § 2144.05. The artisan would have had a reasonable expectation of success based on the cumulative disclosures of Krause et al., “Rapid Microfluidic Immunoassays of Cancer Biomarker Proteins Using Disposable Inkjet-Printed Gold Nanoparticle Arrays” ChemistryOPEN (published 08/2013, referred to herein as Krause) and Centi et al., “A disposable immunomagnetic electrochemical sensor based on functionalised magnetic beads and carbon-based screen-printed electrodes (SPCEs) for the detection of polychlorinated biphenyls (PCBs)” Analytica Chimica Acta (published 03/12/2005, referred to herein as Centi). Krause teaches an electrochemical microfluidic immunoassay for detecting an analyte using a sample to bead ratio of 1:12 (Krause supplemental material, p. S8, para. 2, lines 3-7) and Centi teaches an electrochemical microfluidic immunoassay for detecting an analyte using a sample to bead ratio of about 20:1 (Centi, p. 207, col. 2, para. 3, lines 1-2). An artisan would recognize that when doing immunodetection using beads in a sample, that the relative volumes of the beads and sample need to be optimized in order to maximize the number of beads that can bind to the target analyte within the analyte concentration range. As taught by Krause and Centi, the range of potential sample to bead ratios used in electrochemical microfluidic immunoassay is wide and needs to be optimized. An artisan would recognize that doing so increases the sensitivity of the assay based on the target analyte concentration range.
Regarding claim 4, Otieno teaches contacting the sample with the beads for 30 minutes, which is considered to be about 40 minutes (p. 270, col. 2, para. 1, lines 3-5).
Regarding claim 8, Otieno teaches using a syringe pump to load liquids into the chip (Figure 1, p. 270, col. 1, para. 6, lines 4-6, “injected”).
Regarding claim 10, Otieno teaches the reporter generates an electrochemical signal (p. 270, col. 2, para. 1, lines 17-19).
Regarding claim 12, Otieno teaches the use of horseradish peroxidase as a reporter (p. 270, col. 1, para. 4, lines 1-3), which is a chemiluminescent reporter as described in the instant Specification (p. 6, lines 1-3).
Regarding claim 19, Otieno teaches detecting amperometric current (p.270, col. 2, para. 1, lines 17-19).
Regarding claim 28, Otieno teaches a method that does not comprise centrifuging the sample (p. 270, col. 1, para. 6 – col. 2, para. 1).
Regarding claim 33, Otieno teaches that “The assay requires 30 minutes” (p. 273, col. 2, para. 3, lines 7-8).
Regarding claim 35, Otieno teaches using a sample volume of 5µl (p. 270, col. 1, para. 6, lines 6-7).
However, Otieno does not teach using AC electrothermal flow (ACEF) to mix the sample (claim 1) applied at 200kHz and 25 Vpp (claim 21) for about 5 minutes (claim 22) or performing immunomagnetic enrichment by positioning a magnet proximal to the immunosensor to concentrate the DMBs on the working electrode (claim 1).
Li teaches a method of target protein electrochemical detection in a chip using beads and ACEF for mixing sample and beads (p. 1, col. 2, para. 2, lines 1-3).
Regarding claim 1, Li teaches applying ACEF to mix the sample (p. 555, col. 2, para. 3, lines 1-7). Li teaches that “ACEF-induced mixing can significantly reduce the time for immunocomplex formation compared with incubation-based antigen-antibody binding while also resulting in a higher detection sensitivity due to electrochemical flow-induced removal of nonspecific species from the sensor surface.” (p. 558, col. 1, para. 3, lines 4-9).
Regarding claim 21, Li teaches ACEF applied as 200 kHz (p. 557, col. 1, para. 2, lines 1-6). Li teaches that the level of Vpp was optimized between 1-10 (Figure 6a. p. 557, col. 2, para. 1, lines 1-2). However, it would have been prima facie obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to perform routine optimization of the Vpp level in the claimed invention to make and use the claimed invention. As noted in In re Aller, 105 USPQ 233 at 235, more particularly, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. Routine optimization is not considered inventive and no evidence has been presented that arriving at the claimed 25 Vpp was anything other than routine, that the properties of the 25 Vpp from the optimization has any unexpected properties, or that the results should be considered unexpected in any way as compared to the closest prior art. Optimization of parameters is a routine practice that would be obvious for the artisan to employ. See MPEP § 2144.05. The artisan would have had a reasonable expectation of success based on the cumulative disclosures of Li and Lu et al., “AC Electrokinetics of Physiological Fluids for
Biomedical Applications” Journal of Lab. Automation (published December 2015, referred to herein as Lu). As taught by Li, the value of Vpp should be optimized for the assay (p. 557, col. 2, para. 1, lines 1-2) and Lu teaches that up to 30 Vpp can be used to manipulate biological samples (p. 615, col. 1, para. 1, lines 1-3). Based on the cumulative teachings of Li and Lu, it would have been obvious to optimize the Vpp levels for the assay between 1 and 30 Vpp.
Regarding claim 22, Li teaches mixing the sample for 5 minutes using ACEF (p. 555, col. 2, para. 3, lines 1-6).
It would have been obvious to one of ordinary skill in the art to modify the method taught by Otieno by including the use of ACEF mixing taught by Li. An artisan would have been motived to make this modification because the use of ACEF increases the specificity and formation speed of antigen-antibody immunocomplexes in bead-based immunoassays, as taught by Li. An artisan would have a reasonable expectation of success because the methods taught by Otieno and Li both are directed toward the detection of a target protein using immobilized antibodies and antibody-conjugated beads in a sandwich-type method on a microfluidic chip. Li has shown that ACEF can be successfully incorporated into these types of assays.
Regarding claim 33, the combined teachings of Otieno and Li would result in a 5 minute mixing step and a 15 minute capture step (Otieno, p. 270, col. 2, para. 1, lines 13-17), which is less than 30 total minutes.
However, the combined teachings of Otieno in view of Li do not teach performing immunomagnetic enrichment by positioning a magnet proximal to the immunosensor to concentrate the DMBs on the working electrode (claim 1).
Wei teaches a method of detecting a target protein in a sample comprising contacting the immunosensor with magnetic beads conjugated to a capture antibody and performing immunomagnetic enrichment by positioning a magnet proximal to the immunosensor for electrochemical detection (Scheme 1, p. 4206, col. 1, para. 1, lines 1-4). Wei teaches that magnetic enrichment increased the signal generated by the assay (Figure 2b).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method taught by the combined teachings of Otieno and Li by including the magnetic enrichment step taught by Wei. An artisan would have been motivated to make this change because, as taught by Wei, the magnetic enrichment increases the signal generated by the assay. An artisan would have had a reasonable expectation of success in making this change because the magnetic enrichment step taught by Wei and the detection methods taught by Otieno in view of Li both use an immunodetection method with an electrochemical immunosensor comprising a working electrode, a counter electrode, and a reference electrode and magnetic beads and use magnets to influence the beads.
Claims 14 is rejected under 35 U.S.C. 103 as being unpatentable over Otieno in view of Li and Wei as applied to claim 1 above, and further in view of Hou et al., “A colorimetric and electrochemical immunosensor for point-of-care detection of enterovirus 71” Biosensors and Bioelectronics (published 07/14/2017, IDS dated 03/08/2024, referred to herein as Hou).
The teachings of Otieno in view of Li and Wei, as discussed above regarding claim 1, are incorporated herein.
Regarding claim 14, Otieno teaches a method comprising a bead conjugated to an antibody and HRP (p. 270, col. 1, para. 4, lines 1-3). In this case, the antibody is considered to be conjugated to HRP through conjugation to the bead.
However, Otieno in view of Li does not teach detecting a colorimetric signal.
Regarding claim 14, Hou teaches a method of protein detection using a magnetic bead conjugated to HRP and a detection antibody (Scheme 1, p. 187, col. 2, para. 3, lines 1-2). Hou teaches that these beads can be used to detect a colorimetric signal (p. 187, col. 1, para. 2, lines 5-13). Hou teaches that the colorimetric detection of the protein is convenient because it can be read without any instruments and enables easy point-of-care detection (p. 189, col. 1, para. 1, lines 5-11).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method taught by Otieno in view of Li and Wei by detecting the protein using colorimetric detection as taught by Hou. An artisan would have been motivated to make this modification because, as taught by Hou, colorimetric detection is convenient and enables point-of-care detection without instrumentation. An artisan would have had a reasonable expectation of success in making this modification because the methods taught by Otieno and Hou both use beads conjugated to the detection antibody and an HRP reporter which, as taught by Hou, can be used for both colorimetric and electrochemical detection.
Response to Arguments
Applicant's arguments filed 04/27/2026 have been fully considered but they are not persuasive for the following reasons:
Regarding the remarks on pages 6 and 7 regarding the rejection of claims 1, 3, and 14 under 35 U.S.C. 112(b), the rejection has been withdrawn in response to Applicant’s amendment.
Regarding the remarks on page 8, para. 1 to page 9, para. 1, Applicant argues that Otieno and Li do not teach the amended limitation of using immunomagnetic enrichment via a magnet positioned proximal to the immunosensor.
This argument is not persuasive. As detailed above in the amended rejection under 35 U.S.C. 103, the teachings of Otieno and Li are not relied upon to teach the limitation of immunomagnetic enrichment via a magnet positioned proximal to the immunosensor. Wei does teach immunomagnetic enrichment via a magnet positioned proximal to the immunosensor and teaches a motivation to include it in methods related to electrochemical detection of targets using magnetic beads in an immunoassay.
Regarding the remarks on page 9, para. 2, Applicant argues that the claimed invention demonstrates unexpected and surprising results that produces significant performance improvement.
This argument is not persuasive. An artisan would recognize from the teaching of Li that ACEF improves the sensitivity and timing of the method by improving the binding of the beads to the target and that Wei teaches that magnetic enrichment onto the working electrode improves the signal generated by the assay. An artisan would expect for these effects to be additive since they affect different steps of the assay and would both work to improve assay function when combined to have a greater effect than either improvement individually. Further, an artisan would be motivated to include these improvements on the merits of each improvement individually regardless of whether the synergistic effect is greater than their expectation.
Regarding the remarks on page 10 on the rejection of claim 14 under 35 U.S.C. 103, Applicant argues that the incorporation of the colorimetric HRP detection into the method taught by Otieno and Li relies on hindsight without any motivation or expectation to achieve Applicant’s demonstrated advantages.
This argument is not persuasive. In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). In this case, the teachings of Hou provide the colorimetric detection using HRP and motivation to make reading the assay more convenient.
In response to Applicant’s argument that the cited references do not teach the advantages demonstrated by the Applicant, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). In this case, an artisan would be motivated to modify the method taught by Otieno and Li with the colorimetric method taught by Hou, as described above, in order to improve the convenience of reading the assay, as taught by Hou.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/C.E./Examiner, Art Unit 1677
/BAO-THUY L NGUYEN/Supervisory Patent Examiner, Art Unit 1677 June 1, 2026
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