Prosecution Insights
Last updated: April 19, 2026
Application No. 15/475,719

SYSTEMS AND METHODS FOR ELECTROCHEMICAL CREATININE ASSAYS

Non-Final OA §103§112
Filed
Mar 31, 2017
Examiner
TRAN, VIVIAN AILINH
Art Unit
1794
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Polymer Technology Systems Inc.
OA Round
15 (Non-Final)
53%
Grant Probability
Moderate
15-16
OA Rounds
3y 9m
To Grant
95%
With Interview

Examiner Intelligence

Grants 53% of resolved cases
53%
Career Allow Rate
100 granted / 189 resolved
-12.1% vs TC avg
Strong +42% interview lift
Without
With
+42.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
25 currently pending
Career history
214
Total Applications
across all art units

Statute-Specific Performance

§101
4.8%
-35.2% vs TC avg
§103
45.3%
+5.3% vs TC avg
§102
10.8%
-29.2% vs TC avg
§112
30.7%
-9.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 189 resolved cases

Office Action

§103 §112
DETAILED ACTION 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 . Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on February 20, 2026 has been entered. Information Disclosure Statement The information disclosure statement filed December 16, 2025 fails to comply with 37 CFR 1.98(a)(3)(i) because it does not include a concise explanation of the relevance, as it is presently understood by the individual designated in 37 CFR 1.56(c) most knowledgeable about the content of the information, of each reference listed that is not in the English language. It has been placed in the application file, but the information referred to therein has not been considered. Response to Amendment This is an office action in response to applicant’s arguments and remarks filed on February 20, 2026. Claims 1-2, 5-6, and 29-31 are pending in the application and are being examined herein. Examiner notes that the status identifier of claim 1 says “Previously presented” but will be treated as “Currently amended” since there is an amendment to the claim in line 8. Status of Objections and Rejections The objection to claim 1 is withdrawn in view of Applicant’s amendment. All rejections from the previous office action are maintained. New grounds of rejection under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, and 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, are necessitated by the amendments. Claim Rejections - 35 USC § 112 The following is a quotation of the first paragraph of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. Claims 29-31 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. New matter is shown in bold. Claims 29-31 recite “the coating dissolves in the blood” (claims 29 and 31) and “the buffer dissolves in the blood” (claim 30). The specification does not contain support for the coating or the buffer dissolving in the blood. There is no disclosure of the coating or the buffer being dissolvable. Applicant is required to cancel the new matter in reply to this Office Action. The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claim 31 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 31 recites “The system of claim 21”. However, claim 21 is cancelled, so it is unclear how to interpret claim 31 and which claim it is dependent from. Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. 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 1-2 and 5-6 are rejected under 35 U.S.C. 103 as being unpatentable over Monbouquette (US 6,241,863 B1) in view of Siedel et al. (US 4,816,393 A) and further in view of Feldman et al. (US 2017/0121754 A1). Regarding claim 1, Monbouquette teaches a system for the electrochemical detection of creatinine levels (a creatinine biosensor for electrochemical measurements of creatinine, Monbouquette, Figs. 13-14 & 18, col. 14, lns. 38-48, col. 21, lns. 9-25), the system comprising: a test strip including an electrode and a counter electrode, the electrode and counter electrode located proximate to a sample reception area (a working electrode and a counter electrode located proximate to the injected sample, Monbouquette, Fig. 13, col. 21, lns. 8-23); and a coating on one of the electrode and counter electrode, the coating including a reagent coating for creatinine, wherein the reagent coating includes sarcosine dehydrogenase and a mediator, the mediator being potassium ferricyanide (mediators and enzymes for sensing creatinine are adsorbed on the surface of the working electrode, Monbouquette, Fig. 13, col. 4, lns. 13-31, col. 6, lns. 12-13, col. 11, lns. 57-65, col. 12, lns. 19-21, the enzymes include sarcosine dehydrogenase, Monbouquette, Fig. 13, col. 4, lns. 13-18, col. 11, lns. 57-63; mediators such as potassium ferricyanate are utilized with the sarcosine dehydrogenase, Monbouquette, col. 4, lns. 28-31, col. 12, lns. 10-21, Examiner interprets "potassium ferricyanate" to be potassium ferricyanide), wherein the reagent coating for creatinine is not dependent on oxygen (the utilization of sarcosine dehydrogenase in the creatinine biosensor eliminates the requirement for oxygen, Monbouquette, col. 12, lns. 10-12), wherein the coating is configured such that when creatinine is present in the blood sample the system detects creatinine (the creatinine biosensor comprising the enzymes is configured to detect creatinine in human serum, Monbouquette, col. 11, lns. 54-60). Monbouquette teaches that the enzymes adsorbed on the surface of the working electrode include creatinine amidohydrolase, creatine amidinohydrolase, and sarcosine dehydrogenase, which are involved in the metabolic pathway of creatinine to sarcosine for measurement of creatinine (Monbouquette, Figs. 7 & 13, col. 4, lns. 13-18, col. 11, lns. 57-67, col. 12, lns. 1-9). Monbouquette fails to teach wherein the reagent coating further includes 1-methylhydantoinase (NMHase) enzyme, N-carbamoylsarcosine amidohydrolase (CSHase) enzyme, and creatinine deiminase. Siedel teaches determination of creatinine by detection of sarcosine (Siedel, abstract). Siedel teaches determination of creatinine by conversion of the creatinine with creatinine deiminase into 1-methylhydantoin, hydrolysis of the latter with 1-methylhydantoinase (NMHase), and determination of the hydrolysis product formed from 1-methylhydantoin leading to the formation of sarcosine in the presence of N-carbamoylsarcosine amidohydrolase (CSHase), and detection of sarcosine with sarcosine dehydrogenase (Siedel, col. 6, lns. 6-17, col. 7, lns. 1-5, 51-55). Thus, Siedel teaches that the combination of creatinine deiminase, NMHase, and CSHase can convert creatinine to sarcosine (Siedel, col. 6, lns. 6-15), just as the combination of creatinine amidohydrolase and creatine amidinohydrolase taught by Monbouquette can also convert creatinine to sarcosine (Monbouquette, Fig. 7, col. 11, lns. 66-67). It would have been obvious for one having ordinary skill in the art before the effective filing date of the claimed invention to substitute the creatinine amidohydrolase and creatine amidinohydrolase of Monbouquette with creatinine deiminase, NMHase, and CSHase as taught by Siedel in order to yield the predictable result of producing sarcosine from creatinine, and detecting sarcosine to determine creatinine (Siedel, col. 6, lns. 6-17). Simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 127 8S. Ct. 1727, 82 U.S.P.Q.2d 1385 (2007); MPEP § 2143(I)(B). Furthermore, the selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. MPEP § 2144.07. Modified Monbouquette teaches an embodiment where creatinine was injected into the electrochemical cell using a 50 µL microsyringe (Monbouquette, col. 21, lns. 21-23). Modified Monbouquette is silent with respect to the size of the sample reception area. Modified Monbouquette fails to teach that the sample reception area is capable of wicking blood into the test strip, wherein the sample reception area is sized to receive approximately 1.2 microliters. Feldman teaches an electrochemical test strip comprising a reagent system for analyzing a sample (Feldman, abstract). Feldman teaches that the sample may be a blood sample, e.g. serum (Feldman, para. [0053]). Feldman teaches that the test strip comprises a sample chamber disposed on the electrodes, such that a sample applied at the tip of the test strip contacts the electrodes (Feldman, Fig. 1, para. [0074]). Feldman teaches that a layer of mesh may overlay the electrodes to protect the sensing layer from physical damage, and that the mesh layer facilitates filling of the sample chamber by wicking the sample into the sample chamber (Feldman, para. [0068]). Feldman teaches that the sample chamber has a volume sufficient to receive a sample therein, and may be no more than about 2 µL (Feldman, para. [0066]). It would have been obvious for one having ordinary skill in the art before the effective filing date of the claimed invention to modify the sample reception area of Modified Monbouquette to have a volume of about 2 µL and a mesh layer overlaying the electrodes for wicking the sample as taught by Feldman because the mesh layer can protect the electrodes from physical damage, and the volume of 2 µL would yield the predictable result of receiving the sample. It has been held that obviousness exists where the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have the same properties. Titanium Metals Corp. of America V. Banner, 778 F.2d 775, 227 USPQ 773 (Fed. Cir. 1985). See MPEP § 2144.05(I). In the instant case, the sample reception area disclosed by Modified Monbouquette serves the purpose of receiving the sample. Thus, it is obvious to have a sample reception area that is approximately 1.2 µL because such volume, although not explicitly disclosed by Modified Monbouquette, would serve the same purpose and provide the same properties as the 2 µL volume that is disclosed by Modified Monbouquette. Furthermore, the Federal Circuit has held that, where the only difference between the prior art and the claims was a recitation of relative dimensions of the claimed device and a device having the claimed relative dimensions would not perform differently than the prior art device, the claimed device was not patentably distinct from the prior art device. MPEP § 2144.04(IV)(A). The limitations "for the electrochemical detection of creatinine levels," "capable of wicking blood into the test strip," "for creatinine," "not dependent on oxygen," "receive approximately 1.2 microliters," and "detects creatinine" are interpreted as intended use and/or functional language. The Courts have held that the manner in which a claimed apparatus is intended to be employed does not differentiate an apparatus claim from the prior art, if the prior art apparatus teaches all of the structural limitations of the claim. See Ex parte Masham, 2 USPQ2d 1647 (BPAI 1987). A functional recitation of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. See MPEP § 2114. The creatinine biosensor of Modified Monbouquette teaches all of the structural limitations of the claim and thus is configured for and capable of performing the intended use and/or functional language as recited in the rejection supra. Furthermore, the limitations "a blood sample", "creatinine is present in the blood sample", and "the blood sample is approximately 1.2 microliters" are with respect to an article worked upon (the blood sample and creatinine) and not a positively recited element of the system. Inclusion of the material or article worked upon (the blood sample and creatinine) by a structure (the system) being claimed does not impart patentability to the claims. The claims are directed to an apparatus (the system) which works upon an article or material (the blood sample and creatinine) in its intended use. MPEP § 2115. Examiner further notes that Modified Monbouquette teaches that the reagent coating of the creatinine biosensor is not oxygen dependent (the utilization of sarcosine dehydrogenase in the creatinine biosensor eliminates the requirement for oxygen, Monbouquette, col. 12, lns. 10-12), so the creatinine biosensor of Modified Monbouquette does not require a greater volume of sample since there would not be a need to dampen out oxygen interference, and thus is configured for and capable of performing the intended use language "the blood sample is approximately 1.2 microliters." Regarding claims 2 and 5-6, Modified Monbouquette teaches wherein the reagent coating includes a surfactant, a binder, stabilizers, and a buffer, of instant claim 2, wherein the reagent coating includes a surfactant and a buffer, of instant claim 5, and wherein the buffer includes a binder and a stabilizer, of instant claim 6 (the working electrode is modified with: a surfactant, Monbouquette, col. 9, lns. 42-44, a binder to facilitate electrostatic binding of the enzymes, Monbouquette, col. 3, lns. 58-63, a stabilizer, Monbouquette, col. 4, lns. 36-38, claim 3, and a phosphate buffer, Monbouquette, col. 6, lns. 15-17 & 34-36). Response to Arguments Applicant's arguments filed February 20, 2026 have been fully considered but they are not persuasive. In the arguments presented on page 4 of the amendment, Applicant argues that Monbouquette cannot teach the use of potassium ferricyanide in a creatinine assay because Monbouquette teaches that only phenazine methosulfate and 2,6-diclorophenol indophenol served as effective mediators for the creatine and creatinine systems (col. 14, lns. 58-65). Examiner respectfully disagrees. Monbouquette explicitly teaches that potassium ferricyanate (potassium ferricyanide) can be used as a mediator for a three-enzyme system including sarcosine dehydrogenase, creatine amidinohydrolase, and creatinine amidohydrolase for detection of sarcosine, creatine, and/or creatinine (Fig. 7, col. 4, lns. 13-31, col. 11, lns. 55-67, col. 12, lns. 1-21). Therefore, Monbouquette does not teach away from using potassium ferricyanide as a mediator in a creatinine assay. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to VIVIAN A TRAN whose telephone number is (571)272-3232. The examiner can normally be reached Mon - Fri 9am-5pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, James Lin can be reached at (571) 272-8902. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /V.T./ Examiner, Art Unit 1794 /JAMES LIN/ Supervisory Patent Examiner, Art Unit 1794
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Prosecution Timeline

Mar 31, 2017
Application Filed
Apr 15, 2019
Non-Final Rejection — §103, §112
Oct 18, 2019
Response Filed
Jan 17, 2020
Final Rejection — §103, §112
Jul 23, 2020
Request for Continued Examination
Jul 24, 2020
Response after Non-Final Action
Aug 17, 2020
Non-Final Rejection — §103, §112
Feb 22, 2021
Response Filed
May 07, 2021
Final Rejection — §103, §112
Nov 12, 2021
Request for Continued Examination
Nov 15, 2021
Response after Non-Final Action
Nov 18, 2021
Non-Final Rejection — §103, §112
May 23, 2022
Response Filed
Jun 17, 2022
Final Rejection — §103, §112
Nov 22, 2022
Request for Continued Examination
Nov 28, 2022
Response after Non-Final Action
Nov 30, 2022
Non-Final Rejection — §103, §112
May 15, 2023
Response Filed
Jun 30, 2023
Final Rejection — §103, §112
Nov 13, 2023
Request for Continued Examination
Nov 14, 2023
Response after Non-Final Action
Nov 21, 2023
Non-Final Rejection — §103, §112
May 29, 2024
Response Filed
Jun 13, 2024
Final Rejection — §103, §112
Sep 19, 2024
Request for Continued Examination
Sep 20, 2024
Response after Non-Final Action
Sep 30, 2024
Non-Final Rejection — §103, §112
Jan 02, 2025
Response Filed
Jan 17, 2025
Final Rejection — §103, §112
May 27, 2025
Request for Continued Examination
May 28, 2025
Response after Non-Final Action
May 30, 2025
Non-Final Rejection — §103, §112
Oct 03, 2025
Response Filed
Oct 15, 2025
Final Rejection — §103, §112
Feb 20, 2026
Request for Continued Examination
Feb 26, 2026
Response after Non-Final Action
Feb 27, 2026
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

15-16
Expected OA Rounds
53%
Grant Probability
95%
With Interview (+42.5%)
3y 9m
Median Time to Grant
High
PTA Risk
Based on 189 resolved cases by this examiner. Grant probability derived from career allow rate.

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