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 .
Applicant’s amendment filed 4/27/2026 is acknowledged.
All of the remaining amended claims filed on 4/27/2026, claims 1 and 3-9, are under examination on the merits.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 5/22/2026 has been entered.
Response to Arguments
Applicant's arguments filed 4/27/2026 have been fully considered but they are not persuasive. See below.
Additionally, new objections and rejections under 35 U.S.C. §112(b) are raised below.
Maintained Rejections
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.
(Previous Rejection Maintained) Claims 1 and 3-9 are rejected under 35 U.S.C. 103 as being unpatentable over Hermens et al. (WO 2013036118 A1, published 3/14/2013; hereinafter referred to as “Hermens”) in view of Woods (Biotechnol Bioeng. 2014 Mar;111(3):545-51. doi: 10.1002/bit.25112. Epub 2013 Sep 25. PMID: 24018957).
Response to arguments
Applicant presents the following arguments:
One of skill in the art would not be led to combine the teachings of Hermens and Woods in the manner set out by the Office. Hermens does not teach pressure reduction at all. Woods simply fails to teach a controlled reduction in pressure to minimize the passage of larger viruses through the filter (which is now more explicitly in claim 1 as amended). There is no pointer leading one of skill in the art to combine Hermens’ steady filtration conditions and Woods’ pressure-dropping filtration conditions, since the two conditions would serve opposing purposes.
Dependent claims 3-6 are also allowable, not only because they depend directly or indirectly from novel and non-obvious independent claim 1, but in view of the deficiencies such that one of skill in the art would not combine the teachings of the cited references, there is no pointer leading to the claimed duration of the reduced pressure.
Thus, a consideration of the factors set out in Graham v. John Deere Co., 383 US 1 148 USPQ 459 (1996) indicates that the presently claimed aspect of the invention is unobvious to one of ordinary skill in the art at the relevant time in view of the combined disclosures of the cited references.
Since the independent claim is allowable for the reasons set forth above, the dependent claims are allowable as they depend from the novel and non-obvious independent claim.
Applicant’s arguments were carefully considered but are found unpersuasive:
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Applicant is mischaracterizing the goals of the references. Each reference is drawn to viral purification. Regarding Applicant’s assertion that there is no pointer, there is an advantage to improved yield, as indicated by Woods. Additionally, there is no requirement that an “express, written motivation to combine must appear in prior art references before a finding of obviousness.” See Ruiz v. A.B. Chance Co., 357 F.3d 1270, 1276, 69 USPQ2d 1686, 1690 (Fed. Cir. 2004).
The "mere existence of differences between the prior art and an invention does not establish the invention’s nonobviousness." Dann v. Johnston, 425 U.S. 219, 230, 189 USPQ 257, 261 (1976). The gap between the prior art and the claimed invention may not be "so great as to render the [claim] nonobvious to one reasonably skilled in the art." Id. In determining obviousness, neither the particular motivation to make the claimed invention nor the problem the inventor is solving controls. The proper analysis is whether the claimed invention would have been obvious as of the relevant time to one of ordinary skill in the art after consideration of all the facts. See 35 U.S.C. 103 or pre-AIA 35 U.S.C. 103(a). See MPEP §2141(III).
Regarding the new limitations “such that viruses having a size of 45 nanometers or larger are retained by the porous filter”, “minimizing the passage of viruses having a size of 45 nanometers or larger through the porous filter” and “such that viruses smaller than 40 nanometers in size pass through the porous filter while viruses having a size of 45 nanometers or larger are retained by the porous filter”, it would have been obvious to one of ordinary skill in the art to select and use a filter with a proper size that would allow smaller viruses less than 40 nanometers in size to pass through the porous filter while retaining viruses having a size of 45 nanometers or larger. Hermens discloses that the size of the filter may be such to remove particles having a size of approximately 40-400 nm, and that the viruses size difference may be as little as 5 nm, or less.
Regarding Applicant’s assertion that there is no pointer leading to the claimed duration of the reduced pressure, Woods discloses that the pressure may be lowered to 0 psi for 5 minutes, which is at least 2 minutes, at least 5 minutes, or within the range of 2 minutes to 15 minutes, as instantly claimed (claims 4-6). One of ordinary skill in the art would have been motivated to choose the claimed value or range to increase the concentration of the smaller virus in the filtrate, as disclosed by Woods.
Accordingly, Applicant’s arguments are found to be unpersuasive, and the rejection under 35 U.S.C. §103 is maintained.
New Objection
Specification
The use of the term “tween”, which is a trade name or a mark used in commerce, has been noted in this application on para. [0023]. The term should be accompanied by the generic terminology; furthermore the term should be capitalized wherever it appears or, where appropriate, include a proper symbol indicating use in commerce such as ™, SM , or ® following the term.
Although the use of trade names and marks used in commerce (i.e., trademarks, service marks, certification marks, and collective marks) are permissible in patent applications, the proprietary nature of the marks should be respected and every effort made to prevent their use in any manner which might adversely affect their validity as commercial marks.
New Rejection
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 1 and 3-9 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 1 recites the claim limitation “differential pressure”, which is not defined by the specification. In determining the broadest reasonable interpretation of the term “differential pressure”, the examiner must consider the prior art. Differential pressure is the measurement of pressure difference between two points (Mid-West Instrument, 2-page printout, 6/17/2022, accessed on 7/8/2026 at https://midwestinstrument.com/2022/06/17/what-is-the-difference-between-differential-gauge-and-absolute-pressure-measurement/; p. 2).
The metes and bounds of claim 1 are unclear because it is not clear which two points in claimed method are being measured for the required differential pressures required by the claims. Claims 3-9 depend from claim 1 but do not resolve this lack of clarity. Accordingly, claims 1 and 3-9 are rejected as being indefinite.
Conclusion
No claim is allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JEFFREY MARK SIFFORD whose telephone number is 571-272-7289. The examiner can normally be reached 8:30 a.m. - 5:30 p.m. ET with alternating Fridays off.
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, Michael Allen can be reached at 571-270-3497. 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.
/JEFFREY MARK SIFFORD/Examiner, Art Unit 1671
/Michael Allen/Supervisory Patent Examiner, Art Unit 1671
Prosecution Insights