DETAILED ACTION
Applicant’s amendment dated 19 May 2026 is acknowledged. Claims 1-17 and 27-32 as amended are pending, with claims 9-17 withdrawn.
Claim Rejections - 35 USC § 112
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.
Claims 27-29 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 27 (from which claims 28 and 29 depend) recites the limitation "the matrix" in lines 9 and 14. There is insufficient antecedent basis for this limitation in the claim.
For the purpose of applying prior art, it is presumed that “matrix” refers to the previously recited “porous size exclusion support”.
Claim Rejections - 35 USC § 103
Claims 1-8 and 27-32 are rejected under 35 U.S.C. 103 as being unpatentable over WO 2021/050578 A1 (“Ganapathy”) in view of US 2016/0367966 (“Maloisel”).
As to claims 1, 2, and 4-7, Ganapathy teaches a size exclusion support (para. 165) that is porous (para. 96). Ganapathy teaches covalently modifying the porous support with polyethyleneimine, which is a cationic moiety as required by claims 1, 4, and 5, and the support is made of hydroxyethylcellulose as required by claims 1 and 6, and has a cutoff of 40K (para. 0165). Given the identity of the support, it may be considered a matrix.
Ganapathy teaches the use of hydroxyethyl cellulose porous supports, but does not discuss crosslinking with epichlorohydrin. Maloisel teaches a similar separation matrix for purification having porous particles that have been amine functionalized (abstract), the porous matrix being of polysaccharide (para. 0050), and teaches the utility of crosslinking the support particles with epichlorohydrin as required by claims 1 and 7. It would be obvious to modify the supports of Ganapathy using epichlorohydrin, as Maloisel teaches the utility of crosslinking polysaccharide particles for use as chromatography supports.
Ganapathy teaches that the material is capable separating by charge, but does not specifically state that the material associates with a sample with an isoelectric point ranging from 4.6 to 5.5 and passes at least one molecule with a charge of 8.0 and 11.5, or specifically a protein having isoelectric point ranging from 4.5 to 5.5 and a molecular weight from 50 to 80 kDa as required by claim 2. This limitation is characterized as an intended use. Since Ganapathy in view of Maloisel teaches a matrix modified with the same cationic modifying material, polyethyleneimine, it is presumed to be capable of associating one sample molecule of 4.5 to 5.5 isoelectric point, while passing a molecule having an isoelectric point of 8.0 to 11.5.
As to claim 3, Ganapathy teaches forming formaldehyde groups on hydroxyethyl cellulose to which polyethyleneimine is coupled using Schiff based chemistry (para. 0165), which as shown at para. 0105, is a reductive amination process. Ganapathy is silent as to the concentration of cationic moieties. However, this is interpreted as a product by process limitation, for which patentability is determined by the end product. It is presumed that the material of Ganapathy has the same modification as that produced with the recited concentration of cationic moieties.
As to claims 8, 31, and 32, Ganapathy teaches a spin column, thus a columnar container that spins, and thus is configured for centrifugal force operation, and a tube for collecting flow through, thus a receptacle (para. 178).
As to claim 30, while not exemplified, Ganapathy teaches applying a sample using gravity flow (para. 0018), and thus a container configured for gravity flow is an obvious modification suggested by Ganapathy.
As to claim 27, Ganapathy teaches a size exclusion support (para. 165) that is porous (para. 96). Ganapathy teaches covalently modifying the porous support with polyethyleneimine, which is a cationic moiety, and the support is made of hydroxyethylcellulose, and has a cutoff of 40K (para. 0165). Given the identity of the support. This porous size exclusion support is presumed to be a matrix.
Ganapathy teaches the use of hydroxyethyl cellulose porous supports, but does not discuss crosslinking with epichlorohydrin. Maloisel teaches a similar separation matrix for purification having porous particles that have been amine functionalized (abstract), the porous matrix being of polysaccharide (para. 0050), and teaches the utility of crosslinking the support particles with epichlorohydrin. It would be obvious to modify the supports of Ganapathy using epichlorohydrin, as Maloisel teaches the utility of crosslinking polysaccharide particles for use as chromatography supports.
Ganapathy teaches a kit containing the support (para. 153) and instructions for employing kit components, which components includes the porous size exclusion support/matrix (para. 160).
Ganapathy teaches that the material is capable separating by charge, but does not specifically state that the material associates with a sample with an isoelectric point ranging from 4.6 to 5.5 and passes at least one molecule with a charge of 8.0 and 11.5. This limitation is characterized as an intended use. Since Ganapathy in view of Maloisel teaches a matrix modified with the same cationic modifying material, polyethyleneimine, it is presumed to be capable of associating one sample molecule of 4.5 to 5.5 isoelectric point, while passing a molecule having an isoelectric point of 8.0 to 11.5.
As to claim 28, Ganapathy teaches the kit having a container containing the porous support, a receptacle for flow through (para. 0153).
As to claim 29, the equilibration buffer is optional under claim 28; since Ganapathy teaches a container and receptacle, and thus the limitation is met. However, Ganapathy also teaches the use of buffers in the kit (para. 0155); while not specifying equilibration buffers, Ganapathy teaches the use of the resin in combination with borate (para. 0180).
Response to Arguments
Applicant's arguments filed 19 May 2026 have been fully considered but they are not persuasive.
The prior rejections under 35 USC 102 have been replaced by rejections under 35 USC 103 over Ganapathy in view of Maloisel.
Applicant’s arguments that Ganapathy in view of Maloisel do not disclose the recited characteristic of binding molecules in the range of 4.5 to 5.5, while passing molecules have isoelectric point of 8.0 to 11.5 is not persuasive. Given that the cationic moieties are the same as recited (polyethyleneimine), it is reasonable to presume that a matrix modified with such cationic moiety will bind a molecule in the lower isoelectric range, while passing at least one molecule in the higher isoelectric range. Applicant’s evidence of improved characteristics for the recited size exclusion and cationic moieties is not persuasive given that Ganapathy teaches the same size exclusion and cationic moieties.
Applicant argues that the combination of Ganapathy with Maloisel is to improve rigidity of the matrix, and does not suggest the improvement. However, as discussed above, since Ganapathy teaches the same size exclusion and cationic moieties, it is presumed to have the same characteristic.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KREGG T BROOKS whose telephone number is (313)446-4888. The examiner can normally be reached Monday to Friday 9 am to 5:30 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, Arrie Reuther can be reached at (571)270-7026. 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.
/KREGG T BROOKS/ Primary Examiner, Art Unit 1764
Prosecution Insights