Prosecution Insights
Last updated: April 19, 2026
Application No. 17/937,251

SURFACE FUNCTIONALIZED AFFINITY MEMBRANES

Non-Final OA §102§103§112§DP
Filed
Sep 30, 2022
Examiner
EMCH, GREGORY S
Art Unit
1678
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Nanopareil LLC
OA Round
1 (Non-Final)
50%
Grant Probability
Moderate
1-2
OA Rounds
3y 7m
To Grant
93%
With Interview

Examiner Intelligence

Grants 50% of resolved cases
50%
Career Allow Rate
305 granted / 615 resolved
-10.4% vs TC avg
Strong +44% interview lift
Without
With
+43.6%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
37 currently pending
Career history
652
Total Applications
across all art units

Statute-Specific Performance

§101
7.5%
-32.5% vs TC avg
§103
29.7%
-10.3% vs TC avg
§102
19.7%
-20.3% vs TC avg
§112
22.1%
-17.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 615 resolved cases

Office Action

§102 §103 §112 §DP
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 . DETAILED ACTION Responsive to communication entered 12/10/2025. Priority This application, filed 09/30/2022, Pub. No. US 2023/0149832, published 05/18/2023, is continuation of application No. PCT/US2021/025438, filed 04/01/2021, which claims priority to provisional application No. 63/003,629, filed 04/01/2020. Status of Claims Claims 1-8, 12, 14-19, 21, 37-41 and 43-58 are currently pending. Claims 1-27 have been originally filed. Claims 1, 3-8, 12, 14-19, 21, 37, 39-40, 43 and 44 have been amended; Claims 9-11, 13, 20, 22-36 and 42 have been canceled; and Claims 45-58 have been added, as set forth in Applicant’s Preliminary amendment filed 02/28/2023. Claims 1-8, 12, 14-19, 21, 37-41 and 43-58 have been subject to restriction/election requirement mailed 10/10/2025. Claim 19 has been amended, as set forth in Applicant’s amendment filed 12/10/2025. Claims 5, 15, 19, 21, 37-41 and 43-58 are withdrawn from further consideration. Claims 1-4, 6-8, 12, 14 and 16-18 are examined. Election/Restrictions Applicants’ election, with traverse, of Group I, Claims 1-8, 12 and 14-18, drawn to an affinity membrane comprising: a membrane support; wherein the membrane support is a cast membrane support, an electrospun membrane support, or a combination thereof; a plurality of linear spacer arms of determined length immobilized on the membrane support; wherein the linear spacer arms each comprise a terminus; and a ligand coupled to the terminus; wherein the ligand comprises a peptide, a protein, or both, and election, with traverse, of the species: (a) an electrospun membrane support comprising cellulose as a membrane support; (b) 1,4-butanediol diglycidyl ether as a linear spacer arm; (c) Protein A as a ligand; (d) an amine group as an inert functional group; (e) an immunoglobin (IgG) as a target, in the reply filed 12/10/2025 is acknowledged and entered. Although required, Applicant did not identify the claims encompassing the elected species. The Examiner believes that Claims 1-4, 6-8, 12, 14 and 16-18 of the elected Group I encompass the elected species (a)-(e), whereas Claim 5 does not read on the elected species (b) and Claim 15 does not read on the elected species (c). Applicant’s traversal of the restriction requirement is on the following grounds: PNG media_image1.png 350 1076 media_image1.png Greyscale PNG media_image2.png 106 1072 media_image2.png Greyscale PNG media_image3.png 282 1066 media_image3.png Greyscale Emphasis in the original. Applicant’s arguments have been fully considered but are not found persuasive for the following reasons. First, the Examiner notes that the products and the methods are not coextensive in their claimed scope and therefore examination of them both would require additional search and consideration and so constitute an undue burden. Second, Applicant’s attention is drawn to MPEP 806.04 and 37 CFR 1.146, which states that, if application contains claims directed to more than a reasonable number of species, the Examiner may require restriction of the claims to not more than a reasonable number of species before taking further action in the application. Since the instant claims are directed to membranes comprising any materials, any linear spacer arms, any peptides and/or proteins as ligands, and any inert functional groups, which constitute unreasonable number of species, the requirement of the election of species is proper. Third, as indicated in the previous Office Action, there would be a serious search and/or examination burden if restriction were not required because the inventions have acquired a separate status in the art in view of their different classification. Furthermore, the inventions require a different field of search and employing different search queries. Accordingly, non-coextensive searches of the patent and non-patent literature would be necessary. In addition, the inventions are likely to raise different non-prior art issues under 35 U.S.C. 101 and/or 35 U.S.C. 112. See the 112 rejections below. The restriction/election requirement is still deemed proper and is therefore made FINAL. Claims 5, 15, 19, 21, 37-41 and 43-58 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to the nonelected inventions/species, there being no allowable generic or linking claim. Applicant timely traversed the restriction/election requirement in the reply filed on 12/10/2025. Information Disclosure Statement The information disclosure statements (IDS) submitted on 03/02/2023, 05/24/2023, 07/11/2023 and 09/10/2025 are in compliance with the provisions of 37 CFR 1.97 and 1.98. Accordingly, the information disclosure statements are being considered by the Examiner. Please note that the following references have bee corrected in the IDS submitted on 07/11/2023: PNG media_image4.png 408 894 media_image4.png Greyscale Specification The disclosure is objected to because of the following informalities: reciting “1,4-butanediol diglycidal ether” instead of “1,4-butanediol diglycidyl ether”. See, for example, page 3: PNG media_image5.png 164 994 media_image5.png Greyscale Emphasis added. Appropriate correction is required. The lengthy specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification. Claim Rejections - 35 USC § 112 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 112 that form the basis for the rejections under this section made in this Office action. The following is a quotation 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 35 U.S.C. 112 (pre-AIA ), first paragraph: 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. 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 8 is 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 pre-AIA the inventor(s), at the time the application was filed, had possession of the claimed invention (“new matter”). At page 9 of the Remarks filed 02/28/2023, Applicant argues that: PNG media_image6.png 160 1066 media_image6.png Greyscale The Examiner respectfully disagrees because the disclosure cited by Applicant in support for the amendment is limited to: PNG media_image7.png 558 1012 media_image7.png Greyscale PNG media_image8.png 686 1012 media_image8.png Greyscale Page 15 of the specification filed 09/30/2022, Emphasis added. PNG media_image9.png 298 992 media_image9.png Greyscale Page 20 of the specification filed 09/30/2022, Emphasis added. As such, there appears to be no support in the specification as filed for a broad recitation “wherein the one or more inert functional groups comprise an anionic group, a cationic group, a neutral group, or combination thereof” in the instant Claim 8. Applicant is reminded that MPEP § 2163.06 requires: I. TREATMENT OF NEW MATTER If new subject matter is added to the disclosure, whether it be in the abstract, the specification, or the drawings, the examiner should object to the introduction of new matter under 35 U.S.C. 132 or 251 as appropriate, and require applicant to cancel the new matter. If new matter is added to the claims, the examiner should reject the claims under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph - written description requirement. In re Rasmussen, 650 F.2d 1212, 211 USPQ 323 (CCPA 1981). The examiner should still consider the subject matter added to the claim in making rejections based on prior art since the new matter rejection may be overcome by applicant. When the claims have not been amended, per se, but the specification has been amended to add new matter, a rejection of the claims under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, should be made whenever any of the claim limitations are affected by the added material. When an amendment is filed in reply to an objection or rejection based on 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, a study of the entire application is often necessary to determine whether or not “new matter” is involved. Applicant should therefore specifically point out the support for any amendments made to the disclosure. Emphasis added. Claims 7, 14 and 16 are 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 7, which depends upon Claim 1, recites the limitation "wherein the nanofiber membrane" in lines 1-2. Emphasis added. There is insufficient antecedent basis for this limitation in Claim 1. PNG media_image10.png 316 1064 media_image10.png Greyscale PNG media_image11.png 82 1014 media_image11.png Greyscale Claim 14 encompasses the products which are defined by parameter “the ligand is present … at density of up to about 1000 mg/g.” In the absence of a known molecular weight, the subject matter of Claim 14 is unclear because mass measures the amount of matter in an object, while the amount of substance counts the number of constituent molecules using moles (mol). Claim 16 recites the limitation "wherein the protein is Protein A, Protein G, or Protein L". There is insufficient antecedent basis for this limitation in the claim because Claim 16 depends upon Claim 15 (withdrawn), which limits the protein to an affimer, an antibody, or an antibody fragment, whereas Claim 16 recites “wherein the protein is Protein A, Protein G, or Protein L.” 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. Claims 1-3, 6, 7, 12, 14 and 16-18 are rejected under 35 U.S.C. 102(a)(1) as anticipated by Hummersone et al., WO 2019/137869 A1, published 07/18/2019, which US counterpart Hummersone et al., US 2021/0060527 has been submitted in the 03/02/2023 IDS. For Applicant’s convenience, the references are made to paragraphs of US 2021/0060527. Regarding Claims 1-3, 7, 12, 16-18 and the elected species (a), (c)-(e), Hummersone et al. teach an affinity nanofiber membrane comprising a membrane support (electrospun cellulose or mix with other polymer), a plurality of linear spacer arms immobilized on the membrane support; wherein the spacer arms each comprise a terminus, and a ligand (protein A) coupled to the terminus via an amine-reactive functional group: PNG media_image12.png 376 610 media_image12.png Greyscale PNG media_image13.png 54 604 media_image13.png Greyscale PNG media_image14.png 170 598 media_image14.png Greyscale PNG media_image15.png 84 602 media_image15.png Greyscale PNG media_image16.png 328 606 media_image16.png Greyscale PNG media_image17.png 492 602 media_image17.png Greyscale PNG media_image18.png 372 602 media_image18.png Greyscale PNG media_image19.png 368 608 media_image19.png Greyscale PNG media_image20.png 444 600 media_image20.png Greyscale PNG media_image21.png 214 608 media_image21.png Greyscale PNG media_image22.png 88 614 media_image22.png Greyscale PNG media_image23.png 190 602 media_image23.png Greyscale PNG media_image24.png 162 600 media_image24.png Greyscale Emphasis added. Regarding Claim 6, the Examiner notes that one of skill in the art would have known that divinyl sulfone (DVS), taught by Hummersone et al., is a highly reactive, bifunctional crosslinking agent commonly used to immobilize biomolecules including antibodies by reacting with nucleophilic groups, specifically targeting amino groups on the target molecules, typically at pH 8–10, as evidenced by: PNG media_image25.png 746 1020 media_image25.png Greyscale Emphasis added. It is further noted that at least some of the ligands, taught by Hummersone et al., such as, for example, peptides at ligand density of 1000 µmol/g, may provide ligand density of up to about 1000 mg/g, recited in Claim 14: PNG media_image26.png 296 764 media_image26.png Greyscale As such, Hummersone et al. teach all structural limitations of the affinity membrane of the instant Claims 1-3, 6, 7, 12, 14, 16-18 and the elected species (a), (c)-(e). 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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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. Claims 1-4, 6-8, 12, 14 and 16-18 are rejected under 35 U.S.C. 103 as obvious over Ma et al., "Electrospun regenerated cellulose nanofiber affinity membrane functionalized with protein A/G for IgG purification," J. Membrane Sci., 2008, vol. 319, No. 1-2, pp. 23-28 (IDS submitted 03/02/2023), in view of Zhang et al., "Increase in IgG-binding Capacity of Recombinant Protein A Immobilized on Heterofunctional Amino and Epoxy Agarose," IOP Conf. Series: Materials Science and Engineering, 2018, vol. 381, No. 012042, 9 pages (IDS submitted 03/02/2023). Ma et al., throughout the publication, and, for example, at Abstract and Section 3.2 at page 25, teach: PNG media_image27.png 462 1096 media_image27.png Greyscale PNG media_image28.png 312 774 media_image28.png Greyscale Emphasis added. Ma et al. do not teach a plurality of linear spacer arms of determined length immobilized on the membrane support, as recited in Claim 1; and one or more inert functional groups immobilized on the surface of the membrane support, as recited in Claim 4. Zhang et al., throughout the publication, and, for example, at Abstract and Figure 1, teach: PNG media_image29.png 584 972 media_image29.png Greyscale Emphasis added. PNG media_image30.png 408 1118 media_image30.png Greyscale It would have been prima facie obvious, before the effective filing date of the claimed invention, for one of ordinary skill in the art to have made and used linear spacer arms and inert functional groups, taught by Zhang et al., in the electrospun regenerated cellulose nanofiber affinity membrane, taught by Ma et al. One of ordinary skill in the art would have been motivated to have made and used linear spacer arms and inert functional groups, taught by Zhang et al., in the electrospun regenerated cellulose nanofiber affinity membrane, taught by Ma et al., because it would be desirable to prepare an affinity membrane with high IgG-binding capacity due to the oriented attachment of protein A on the heterofunctional support, as taught by Zhang et al. One of ordinary skill in the art would have had a reasonable expectation of success in making and using, linear spacer arms and inert functional groups, taught by Zhang et al., in the electrospun regenerated cellulose nanofiber affinity membrane, taught by Ma et al., because one of skill in the art would have considered cellulose, taught by Ma et al., and agarose, taught by Zhang et al., as substituting equivalents known for the same purpose. See MPEP § 2144.06. PNG media_image31.png 174 938 media_image31.png Greyscale PNG media_image32.png 178 962 media_image32.png Greyscale As such, combination of Ma et al. and Zhang et al., teaches all structural limitations of the affinity membrane of the instant Claims 1-4, 6-8, 12, 14, 16-18 and the elected species (a), (c)-(e). With regard to the elected species (b), Sommer-Knudsen, US 2010/0129889 A1, published 05/27/2010, teaches the use of epichlorohydrin or 1,4 butanediol diglycidyl ether for functionalization of a polysaccharide based affinity matrix such as cellulose or agarose: PNG media_image33.png 134 610 media_image33.png Greyscale PNG media_image34.png 60 614 media_image34.png Greyscale PNG media_image35.png 108 600 media_image35.png Greyscale PNG media_image36.png 88 600 media_image36.png Greyscale PNG media_image37.png 248 600 media_image37.png Greyscale Emphasis added. 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 1-4, 6-8, 12, 14 and 16-18 are rejected on the ground of nonstatutory obviousness-type double patenting as being unpatentable over Claims 1-28 of US Patent No. 10,919,986 B2, issued 02/16/2021 (IDS submitted 09/10/2025), in view of Ma et al., "Electrospun regenerated cellulose nanofiber affinity membrane functionalized with protein A/G for IgG purification," J. Membrane Sci., 2008, vol. 319, No. 1-2, pp. 23-28 (IDS submitted 03/02/2023), and Zhang et al., "Increase in IgG-binding Capacity of Recombinant Protein A Immobilized on Heterofunctional Amino and Epoxy Agarose," IOP Conf. Series: Materials Science and Engineering, 2018, vol. 381, No. 012042, 9 pages (IDS submitted 03/02/2023). US Patent No. 10,919,986 B2 claims a hybrid cellulose membrane composition, a method of preparing the composition and a method of using the composition: PNG media_image38.png 354 600 media_image38.png Greyscale PNG media_image39.png 112 606 media_image39.png Greyscale The teachings of Ma et al. and Zhang et al. are discussed above and incorporated herein in its entirety. It would have been prima facie obvious, before the effective filing date of the claimed invention, for one of ordinary skill in the art to have made and used linear spacer arms and inert functional groups, taught by Zhang et al., in the hybrid cellulose membrane composition, claimed by US Patent No. 10,919,986 B2. One of ordinary skill in the art would have been motivated to have made and used linear spacer arms and inert functional groups, taught by Zhang et al., in the hybrid cellulose membrane composition, claimed by US Patent No. 10,919,986 B2, because it would be desirable to prepare an affinity membrane with high IgG-binding capacity due to the oriented attachment of protein A on the heterofunctional support, as taught by Zhang et al. One of ordinary skill in the art would have had a reasonable expectation of success in making and using, linear spacer arms and inert functional groups, taught by Zhang et al., in the hybrid cellulose membrane composition, claimed by US Patent No. 10,919,986 B2, because the use of the electrospun cellulose nanofiber affinity membrane was known in the art, as taught by Ma et al. Claims 1-4, 6-8, 12, 14 and 16-18 are rejected on the ground of nonstatutory obviousness-type double patenting as being unpatentable over Claims 1-31 of US Patent No. 11,560,438 B2, issued 01/24/2023 (IDS submitted 09/10/2025), in view of Ma et al., "Electrospun regenerated cellulose nanofiber affinity membrane functionalized with protein A/G for IgG purification," J. Membrane Sci., 2008, vol. 319, No. 1-2, pp. 23-28 (IDS submitted 03/02/2023), and Zhang et al., "Increase in IgG-binding Capacity of Recombinant Protein A Immobilized on Heterofunctional Amino and Epoxy Agarose," IOP Conf. Series: Materials Science and Engineering, 2018, vol. 381, No. 012042, 9 pages (IDS submitted 03/02/2023). US Patent No. 11,560,438 B2 claims a membrane composition, a method of preparing the composition and a method of using the composition: PNG media_image40.png 240 600 media_image40.png Greyscale PNG media_image41.png 54 600 media_image41.png Greyscale PNG media_image42.png 84 602 media_image42.png Greyscale The teachings of Ma et al. and Zhang et al. are discussed above and incorporated herein in its entirety. It would have been prima facie obvious, before the effective filing date of the claimed invention, for one of ordinary skill in the art to have made and used linear spacer arms and inert functional groups, taught by Zhang et al., in the membrane composition, claimed by US Patent No. 11,560,438 B2. One of ordinary skill in the art would have been motivated to have made and used linear spacer arms and inert functional groups, taught by Zhang et al., in the membrane composition, claimed by US Patent No. 11,560,438 B2, because it would be desirable to prepare an affinity membrane with high IgG-binding capacity due to the oriented attachment of protein A on the heterofunctional support, as taught by Zhang et al. One of ordinary skill in the art would have had a reasonable expectation of success in making and using, linear spacer arms and inert functional groups, taught by Zhang et al., in the hybrid cellulose membrane composition, claimed by US Patent No. 11,560,438 B2, because the use of the electrospun cellulose nanofiber affinity membrane was known in the art, as taught by Ma et al. Claims 1-4, 6-8, 12, 14 and 16-18 are rejected on the ground of nonstatutory obviousness-type double patenting as being unpatentable over Claims 1-27 of US Patent No. 12,479,931 B2, issued 11/25/2025, in view of Ma et al., "Electrospun regenerated cellulose nanofiber affinity membrane functionalized with protein A/G for IgG purification," J. Membrane Sci., 2008, vol. 319, No. 1-2, pp. 23-28 (IDS submitted 03/02/2023), and Zhang et al., "Increase in IgG-binding Capacity of Recombinant Protein A Immobilized on Heterofunctional Amino and Epoxy Agarose," IOP Conf. Series: Materials Science and Engineering, 2018, vol. 381, No. 012042, 9 pages (IDS submitted 03/02/2023). US Patent No. 12,479,931 B2 claims a separation medium, a method of preparing the separation medium and a method of using the separation medium: PNG media_image43.png 328 602 media_image43.png Greyscale PNG media_image44.png 56 600 media_image44.png Greyscale PNG media_image45.png 82 618 media_image45.png Greyscale PNG media_image46.png 170 604 media_image46.png Greyscale The teachings of Ma et al. and Zhang et al. are discussed above and incorporated herein in its entirety. It would have been prima facie obvious, before the effective filing date of the claimed invention, for one of ordinary skill in the art to have made and used linear spacer arms and inert functional groups, taught by Zhang et al., in the separation medium, claimed by US Patent No. 12,479,931 B2. One of ordinary skill in the art would have been motivated to have made and used linear spacer arms and inert functional groups, taught by Zhang et al., in the separation medium, claimed by US Patent No. 12,479,931 B2, because it would be desirable to prepare an affinity membrane with high IgG-binding capacity due to the oriented attachment of protein A on the heterofunctional support, as taught by Zhang et al. One of ordinary skill in the art would have had a reasonable expectation of success in making and using, linear spacer arms and inert functional groups, taught by Zhang et al., in the separation medium, claimed by US Patent No. 12,479,931 B2, because the use of the cellulose nanofiber affinity membrane was known in the art, as taught by Ma et al. Conclusion No claims are allowed. Any inquiry concerning this communication or earlier communications from the examiner should be directed to GALINA M YAKOVLEVA whose telephone number is (571)270-3282. The examiner can normally be reached on M-F 8:30 AM-5:00 PM. 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, GREGORY S EMCH can be reached on (571)272-8149. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /GALINA M. YAKOVLEVA/Primary Examiner, Art Unit 1678
Read full office action

Prosecution Timeline

Sep 30, 2022
Application Filed
Oct 04, 2022
Response after Non-Final Action
Feb 28, 2023
Response after Non-Final Action
Jan 24, 2026
Non-Final Rejection — §102, §103, §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
50%
Grant Probability
93%
With Interview (+43.6%)
3y 7m
Median Time to Grant
Low
PTA Risk
Based on 615 resolved cases by this examiner. Grant probability derived from career allow rate.

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