Prosecution Insights
Last updated: October 23, 2026
Application No. 17/254,886

CRISPR DOUBLE NICKASE BASED AMPLIFICATION COMPOSITIONS, SYSTEMS, AND METHODS

Final Rejection §112
Filed
Dec 22, 2020
Priority
Jun 26, 2018 — provisional 62/690,278 +2 more
Examiner
GREENE, CAROLYN LEE
Art Unit
1681
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
President and Fellows of Harvard College
OA Round
4 (Final)
66%
Grant Probability
Favorable
5-6
OA Rounds
0m
Est. Remaining
99%
With Interview

Examiner Intelligence

Grants 66% — above average
66%
Career Allowance Rate
142 granted / 216 resolved
+5.7% vs TC avg
Strong +46% interview lift
Without
With
+46.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
40 currently pending
Career history
268
Total Applications
across all art units

Statute-Specific Performance

§101
7.7%
-32.3% vs TC avg
§103
36.3%
-3.7% vs TC avg
§102
8.8%
-31.2% vs TC avg
§112
41.7%
+1.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 216 resolved cases

Office Action

§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 . Status of the Application The Responses filed April 27, 2026 and July 20, 2026 are each acknowledged. Claims 1, 3-6, 8-9, 11-12, 14-15, 17-19, 22-23, 25-28, 30-31, 33, 35, 37-38, 40-46 and 48 are pending and are being examined on the merits. Response to Arguments Applicant’s arguments filed April 27, 2026 have been fully considered. The following rejections are WITHDRAWN in view of Applicant’s arguments and amendments to the claims: Rejection of claims 17, 26-28 and 43 under 35 USC § 112(b), indefiniteness The following rejections are MAINTAINED: Rejection of all pending claims under 35 USC § 112(a), lack of enablement Response to arguments regarding lack of enablement rejections Applicant argues that the lack of enablement rejection should be withdrawn and asserts that the rejection contradicts the express claim language of the pending claims (Remarks, p. 11). Applicant provides Figure A on p. 12 of the Remarks as a schematic of some of the claim 1 steps. Figure A is reproduced here, with some additional notations based on Applicant’s statements on p. 12 of the Remarks. PNG media_image1.png 267 647 media_image1.png Greyscale The Examiner disagrees with Applicant’s position for the reasons that follow. In Figure A, the top strand of the double-stranded nucleic acid molecule is referred to as the “first strand” and comprises the “first cut site”. Although not labeled in Fig. A, the bottom strand of the double-stranded nucleic acid molecule is then “second strand” and comprises the “second cut site”. The “first guide molecule” binding site was originally comprised on the top/first strand, but was removed in a prior step, however, the complement of the first guide molecule binding site, which Applicant refers to as the “G1 binding site complement” (labeled as G1 BS’ above) is comprised in the bottom/second strand. The “second guide molecule” binding site was originally comprised on the bottom/second strand, but was removed in a prior step, however, the complement of the second guide molecule binding site, which Applicant refers to as the “G2 binding site complement” (labeled as G2 BS’ above) is comprised in the top/first strand. Claim 1 states that “the first primer comprises a nucleotide sequence that is complementary to a region downstream of the first cutting site on the first target nucleic acid”. In Figure A, as noted, the top/first strand of the target nucleic acid comprises the first cut site. Thus, the “first primer” hybridizes to the top/first strand 3’ (downstream) of the first cut site. Applicant has labeled this “first primer” as “P2” in Figure A. Further, Applicant states in the Remarks, that “P2 anneals to the bottom strand at the G2 binding site complement region” (Remarks, p. 12). It does not. P2 anneals to top strand at the G2 binding site complement region (G2 BS’). Claim 1 further states that “the first primer comprises … a nucleotide sequence that enables regeneration of the first guide molecule binding site upon extension”. Applicant states that this limitation indicates the primer “comprises a portion comprising a binding site for the first guide molecule”1, and further that “P2 … carr[ies] the G2 binding site” (Remarks, p. 12). As noted in Figure A, P2 is the “first primer”, and, claim 1 requires (according to Applicant’s construction of “a nucleotide sequence that enables regeneration …”) that the “first primer” comprises the G1 BS. However, it is seemingly impossible for the first primer/P2 to comprise G1 BS because the G1 BS region is on the opposite end of the molecule and on the opposite strand of the molecule. The “first primer” cannot comprise a sequence that is complementary to the first strand (so that it can hybridize to it), and, simultaneously, comprise a sequence that is identical to a sequence comprised within the first strand, the G1 BS, sequence. In other words, the first primer/P2 cannot comprise sequences from both the top strand and the bottom strand of the molecule at the same time. This is the basis of the lack of enablement rejection. The corresponding analysis applies to the location of the second primer/P1 and G2 BS’, and similarly it is seemingly impossible for the second primer/P1 to comprise G2 BS because the G2 BS region is on the opposite end of the molecule, and on the opposite strand of the molecule. Applicant’s arguments are not persuasive. The rejections are maintained. Information Disclosure Statement The Information Disclosure Statement submitted April 27, 2026 has been considered. Claim Interpretation Independent claim 1 comprises, in part, the following: Step (a)(i): a first CRISPR/Cas complex, comprising a first Cas-based nickase and a first guide molecule that guides the first CRISPR/Cas complex to bind to a first strand of a double-stranded target nucleic acid at a first location and nick the first strand at a first cutting site; and a corresponding second CRISPR/Cas complex with a corresponding second Cas-based nickase and second guide molecule that bind to a second location on the second strand and nick a second cutting site. Step (a)(iii): a primer pair, where the first primer comprises a nucleotide sequence that is complementary to a region downstream of the first cutting site on the first target nucleic acid and a nucleotide sequence that enables regeneration of the first guide molecule binding site upon extension, and a corresponding second primer with a complementary region and nucleotide sequence that correspond to the second target nucleic acid and the second guide molecule binding site. Step (b) (i): nicking a first strand of a double-stranded nucleic acid at the first target nucleic acid location with a first CRISPR/Cas complex and nicking a second strand of a double-stranded nucleic acid at the second target nucleic acid location with a second CRISPR/Cas complex. The resulting structure is shown in instant Fig. 1, second pane: PNG media_image2.png 96 685 media_image2.png Greyscale Step (b) (ii): extending the nicked strands from the 3’ ends of each of the first and second strand cutting sites with a strand-displacing polymerase, as shown in Fig. 1, third pane: PNG media_image3.png 88 671 media_image3.png Greyscale … thereby displacing the downstream strand and generating single-stranded DNA, as follows (for simplicity, only the top/first displaced strand is labeled): PNG media_image4.png 120 359 media_image4.png Greyscale Step (b) (iii): annealing the first primer (P1) to the single-stranded DNA displaced from the first strand downstream of the first cutting site, … and extending the primer[] across the region between the first and second cutting sites to generate a double-stranded amplified product comprising the target nucleic acid sequence between the first and second guide molecule binding sites (for simplicity, only the top/first displaced strand is labeled): PNG media_image5.png 113 336 media_image5.png Greyscale 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 1, 3-6, 8-9, 11-12, 14-15, 17-19, 22-23, 25-28, 30-31, 33, 35, 37-38, 40-46 and 48 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 enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention. In considering whether there is sufficient evidence to support a determination that a disclosure does not satisfy the enablement requirement and whether any necessary experimentation is “undue,” the factors set forth in In re Wands (858 F.2d 731, 737, 8 USPQ2d 1400, 1404 (Fed. Cir. 1988)) should be considered. These factors are: The breadth of the claims, The nature of the invention, The state of the prior art, The level of one of ordinary skill in the art, The level of predictability in the art, The amount of direction provided by the inventor, The existence of working examples; and The quantity of experimentation needed to make or use the invention based on the content of the disclosure. Each of these will be discussed in turn below. Nature of the Invention and the Breadth of the Claims The invention of independent claim 1 is directed to a method of amplifying and detecting a target double-stranded nucleic acid comprising, in part, combining the target nucleic acid with first and second CRISPR/Cas complexes having first and second Cas-based nickases, respectively, and a strand-displacing polymerase. In subsequent steps, the Cas-based nickases nick the target nucleic acid thus creating sub-strands of the target nucleic acid, while the polymerase extends each sub-strand that is located 5’ of a nick and simultaneously displaces each sub-strand that is 3’ of a nick. Claim 1 also recites an additional amplification step where a primer is annealed to each displaced sub-strand and is extended toward the nick site. Finally, claim 1 additionally recites that each of the first and second primer comprises a nucleotide sequence that enables regeneration of the first and second, respectively, guide molecule binding site upon extension. However, since the first and second primers are complementary to and thus anneal to the first and second strand of the target nucleic acid, respectively, and the first and second primers additionally anneal downstream of their corresponding cutting sites, then each primer will anneal to the corresponding displaced sub-strand of the original molecule. Since each displaced sub-strand is no longer attached to the portion of the original molecule which comprises the corresponding guide molecule binding site, it is not possible for the primers to enable regeneration of the site upon extension, as required by claim 1. This is shown above in the claim interpretation step (f). That is, the primer will extend until it reaches the cut site, as the guide molecule binding site is no longer attached to the displaced sub-strand. The dependent claims further define the first and second target locations (claim 3), amplification conditions (claims 4, 17-19), characteristics of the Cas-based nickases (claims 5-6, 8-9, 11-12, 14-15), characteristics of the target nucleic acid sequence and the sample (claims 22-23, 28, 30-31, 33, 35, 37-38, 40), characteristics of the primers (claim 25), and downstream processing steps (26-27). In addition, independent claim 41 is directed to a system for amplifying and/or detecting a target double-stranded nucleic acid, where the limitations correspond closely to the method steps in claim 1. Dependent claims 42-45 are directed to aspects of the system that correspond to some of the aspects of the dependent method claims, and dependent claims 46 and 48 are kits directed to the claim 41 system components. In view of the disclosure in the specification, the claims are not overly broad. The State of the Prior Art Claims 1 and 41 are directed to a method and system, respectively, that essentially use a nicking and extension amplification reaction (NEAR) system, but where the nicking is performed by CRISPR/Cas complexes and Cas-based nickases. Mandell2 (WO 2016/077350) teaches using CRISPR/Cas complexes for amplifying target nucleic acids (e.g., Figs. 1A-1C; paras. 14-15, 28, 60-61, 66-68, 87, 90), while Maples3 (US Patent App. Pub. No. 2009/0017453) teaches NEAR (e.g., Figs. 1A-1C). However, the prior art does not teach sets of primers that have the structures recited in claims 1 and 41, and that function to amplify the target nucleic acid in the manner stated in the claims. Level of One of Ordinary Skill in the Art One of ordinary skill in the art would have the knowledge equivalent to a graduate-level degree in molecular biology. Level of Predictability and Amount of Direction Provided by Inventor While the level of predictability in the art of assays involving nucleic acid amplification is generally high, the specification does not provide any teaching relating to an assay wherein the sets of primers that have the structures recited in claims 1 and 41 function to amplify the target nucleic acid in the manner stated in the claims. Existence of Working Examples The specification provides one working example (paras. 240-246) directed to the using the combined CRISPR and NEAR methods to amplify a target nucleic acid, as well as the use of SHERLOCK detection to detect the amplification products. However, the specification does not provide the sequence or structure of the target nucleic acid, the various CRISPR components (e.g., the guide molecule) or the primers. Quantity of Experimentation Needed to Make or Use the Invention Based on the Content of the Disclosure Considering the disclosures in the specification as a whole, to make and use the invention of instant claims 1 and 41, one of ordinary skill in the art would have to determine how to perform a method or generate a system, respectively, directed to a nicking and extension amplification reaction (NEAR) method which is modified so that the nicking is performed by CRISPR/Cas complexes and Cas-based nickases, and further, to do so with the primer and guide molecule structures described in the claims 1 and 41. As noted above, these primers do not have the capability to function in the method in such a way as to participate in amplification in the described manner, or to interact with the guide molecule binding site limitations, as described. Therefore, the ordinary artisan would have to experiment in order to identify additional steps or structures that would function to allow, e.g., the first primer to anneal to the displaced first strand, which does not comprise the first guide molecule binding site, and somehow still regenerate the first guide molecule binding site during primer extension. Neither the specification, nor the art teaches the ordinary artisan how to do that. If the teachings in the specification provide no more than a “plan” for those of skill in the art to experiment using the technology, the entire breadth of the claims are not enabled. MPEP 2164.06(b). Claims 3-6, 8-9, 11-12, 14-15, 17-19, 22-23, 25-28, 30-31, 33, 35, 37-38 and 40 depend directly or indirectly from claim 1, and consequently incorporate the lack of enablement issues of claim 1. Claims 42-46 and 48 depend directly or indirectly from claim 41 and consequently incorporate the lack of enablement issues of claim 41. For the above reasons, one of ordinary skill in the art would not be able to make and use the claimed invention without undue experimentation. Appropriate correction is required. Conclusion Claims 1, 3-6, 8-9, 11-12, 14-15, 17-19, 22-23, 25-28, 30-31, 33, 35, 37-38, 40-46 and 48 are being examined, and are rejected. No claims are allowed. THIS ACTION IS MADE FINAL. 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to CAROLYN GREENE whose telephone number is (571)272-3240. The examiner can normally be reached M-Th 7:30-5:30 EST. 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 on 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. /CAROLYN L GREENE/Primary Examiner, Art Unit 1681 1 The Examiner does not agree that the claim limitation reciting “the first primer comprises … a nucleotide sequence that enables regeneration of the first guide molecule binding site upon extension” means the same things as a claim limitation reciting “the first primer comprises … a first guide molecule binding site”. However, this issue does not need to be reached here, as Applicant’s arguments are incorrect for other reasons. 2 Mandell was cited in the PTO-892 Notice of References Cited mailed August 27, 2024. 3 Maples was cited in the Information Disclosure Statement submitted November 9, 2023.
Read full office action

Prosecution Timeline

Show 5 earlier events
Jun 19, 2025
Request for Continued Examination
Jun 24, 2025
Response after Non-Final Action
Jul 25, 2025
Response Filed
Jan 28, 2026
Non-Final Rejection mailed — §112
Apr 27, 2026
Response after Non-Final Action
Apr 27, 2026
Response Filed
Jul 20, 2026
Response Filed
Oct 06, 2026
Final Rejection mailed — §112 (current)

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Prosecution Projections

5-6
Expected OA Rounds
66%
Grant Probability
99%
With Interview (+46.1%)
3y 4m (~0m remaining)
Median Time to Grant
High
PTA Risk
Based on 216 resolved cases by this examiner. Grant probability derived from career allowance rate.

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