Prosecution Insights
Last updated: April 19, 2026
Application No. 17/526,743

SINGLE-STEP DNA PREPARATION FOR POLYMERASE CHAIN REACTION USING MAGNETIC CHITOSAN MICROPARTICLES

Non-Final OA §102§103§DP
Filed
Nov 15, 2021
Examiner
MUMMERT, STEPHANIE KANE
Art Unit
1681
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Canon U S A Inc.
OA Round
1 (Non-Final)
60%
Grant Probability
Moderate
1-2
OA Rounds
3y 12m
To Grant
83%
With Interview

Examiner Intelligence

Grants 60% of resolved cases
60%
Career Allow Rate
456 granted / 754 resolved
+0.5% vs TC avg
Strong +22% interview lift
Without
With
+22.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 12m
Avg Prosecution
34 currently pending
Career history
788
Total Applications
across all art units

Statute-Specific Performance

§101
4.0%
-36.0% vs TC avg
§103
46.0%
+6.0% vs TC avg
§102
26.9%
-13.1% vs TC avg
§112
10.5%
-29.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 754 resolved cases

Office Action

§102 §103 §DP
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 . Election/Restrictions Applicant’s election without traverse of Group I, claims 1-14 and species group 1, chitosan (claims 2, 4, 5, 12-13), in the reply filed on February 9 2026 is acknowledged. Claims 3, 6-9 and 15-28 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Further, Applicant elects species Election was made without traverse in the reply filed on February 9, 2026. Claims 1-2, 4-5, 10-14 are pending and will be examined. Information Disclosure Statement The information disclosure statement (IDS) submitted on April 13, 2022 in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1-2, 4-5, 10-14 rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 3-7 of U.S. Patent No. 11174478 (‘478 Patent herein). Although the claims at issue are not identical, they are not patentably distinct from each other because the claims when considered together encompass nearly the same subject matter. The instant claims are a bit more broadly recited than the claims of the ‘478 because the claims of the instant application are focused specifically on the steps of lysis of cells and capturing released nucleic acids onto the microparticles. The claims of the ‘478 patent include a step of amplification directly on the captured nucleic acids and where the amplification occurs in the same buffer as the capture step. However, while the scope of the claims differ, claim 8 of the pending claims includes the additional step of amplification and wherein the purification and amplification occur in the same buffer. Further, when the dependent claims are compared between the instant claims and the claims of the ‘478 patent, very similar subject matter is further encompassed by both sets of claims. Compare instant claim 4 to claim 7 of the ‘478 patent, where the fabrication of chitosan droplets, as claimed, is described. Compare instant claim 14 to claim 6 of the ‘478 patent, where the nucleic acids are acquired from the same kinds of samples including plasmids, bacterial and human genomic DNA. Therefore, while the claims are not identical, the instant claims and the claims of the ‘478 patent encompass entirely overlapping scope of invention and therefore the claims are not patent eligible. Claim Rejections - 35 USC § 102 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. (a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. Claim(s) 1-2, and 10-14 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Petzel et al. (US Patent 8,816,063; August 2014). With regard to claim 1, Petzel teaches a method of purifying nucleic acids from a biological sample comprising one or more cells, the method comprising the steps of: adding microparticles to the biological sample having a PCR amplification compatible pH (col. 11, lines 3-40, where the pH of the binding buffer can be the same for elution of the nucleic acids); lysing the one or more cells in the biological sample by mechanically agitating the biological sample (col. 11, lines 22-40, where the cell material can be disrupted in a variety of ways including physical disruption); and capturing released nucleic acids on the microparticles (col 11, where cells are lysed, nucleic acids are released and they are bound). With regard to claim 2, Petzel teaches a method of purifying nucleic acids from a biological sample comprising the method of claim 1, wherein the microparicles are fabricated from chitosan (col. 9, lines 37-52, where the microparticles are made of chitosan). With regard to claim 10, Petzel teaches a method of purifying nucleic acids from a biological sample comprising the method of claim 1, wherein the step of lysing the one or more cells in the biological sample includes heating the biological sample and vortexing the biological sample (col. 11, lines 22-40, where the cell material can be disrupted in a variety of ways including physical disruption). With regard to claim 11, Petzel teaches a method of purifying nucleic acids from a biological sample comprising the method of claim 1, further comprising separating and washing microparticles with captured nucleic acids (col 11, where cells are lysed, nucleic acids are released and they are bound; col. 2, lines 6-19, col. 11, lines 28-40, where the eluted nucleic acid can be amplified by PCR). With regard to claim 12, Petzel teaches a method of purifying nucleic acids from a biological sample comprising the method of claim 2, wherein the chitosan microparticles provide for cell lysis and simultaneous DNA capture, and then serve as a solid support for a DNA template during a PCR amplification reaction (col 11, where cells are lysed, nucleic acids are released and they are bound; col. 2, lines 6-19, col. 11, lines 28-40, where the eluted nucleic acid can be amplified by PCR). With regard to claim 13, Petzel teaches a method of purifying nucleic acids from a biological sample comprising the method of claim 2, wherein interior of the chitosan microparticle, beneath a charge-switchable shell, remains positively charged at high pH (col. 11, lines 3-40, where the pH of the binding buffer can be the same for elution of the nucleic acids; col 2, lines 6-24, where the charge switchable shell and technology in general is described). With regard to claim 14, Petzel teaches a method of purifying nucleic acids from a biological sample comprising the method of claim 1, wherein nucleic acids are selected from the group consisting of: plasmids, bacterial DNA, and human genomic DNA (col. 11, lines 10-27, where nucleic acids can be purified from human DNA, bacterial cells and plant cells). Claim Rejections - 35 USC § 103 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. 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. Claim(s) 4-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Petzel et al. (US Patent 8,816,063; August 2014) as applied over claims 1-2 and 10-14 above and further in view of Tallury et al. (Chem Commun, 2009, 2347-2349). With regard to claim 4, Tallury teaches a method of purifying nucleic acids from a biological sample comprising the method of claim 2, wherein the chitosan microparticles are fabricated by creating chitosan droplets in oil and then crosslinking the droplets into microparticles (Abstract , p. 2347, col. 2). With regard to claim 5, Petzel teaches a method of purifying nucleic acids from a biological sample comprising the method of claim 4, wherein crosslinking the droplets into microparticles goes into a core of microparticles over time (Abstract , p. 2347, col. 2). It would have been prima facie obvious to one of ordinary skill in the art at the time the invention was made to have adjusted the teachings of Petzel to include the format of chitosan bead formation as taught by Tallury to arrive at the claimed invention with a reasonable expectation for success. Tallury teaches “Ultra-small size NPs have several advantages: (i) due to large surface to volume ratio, it is possible to co-attach targeting molecules, image contrast agents and/or therapeutic drugs to the NP surface, (ii) these NPs would be capable of evading the macrophage capture of the immune system 15,16 and could remain in the circulation for a longer time for effective therapy, (iii) intra-cellular delivery of these NPs would be facilitated and (iv) these NPs could easily travel through the smallest blood capillary (5–6 microns in diameter) allowing uniform distribution in the circulation (p. 2347). Therefore, one of ordinary skill in the art at the time the invention was made would have adjusted the teachings of Petzel to include the format of chitosan bead formation as taught by Tallury to arrive at the claimed invention with a reasonable expectation for success. Conclusion No claims are allowed. All claims stand rejected. Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHANIE KANE MUMMERT whose telephone number is (571)272-8503. The examiner can normally be reached M-F 9:00-5:30. 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, Gary Benzion can be reached at 571-272-0782. 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. /STEPHANIE K MUMMERT/Primary Examiner, Art Unit 1681
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Prosecution Timeline

Nov 15, 2021
Application Filed
Mar 29, 2022
Response after Non-Final Action
Jul 19, 2022
Response after Non-Final Action
Mar 07, 2026
Non-Final Rejection — §102, §103, §DP (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

1-2
Expected OA Rounds
60%
Grant Probability
83%
With Interview (+22.4%)
3y 12m
Median Time to Grant
Low
PTA Risk
Based on 754 resolved cases by this examiner. Grant probability derived from career allow rate.

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