Prosecution Insights
Last updated: April 19, 2026
Application No. 17/274,000

RAPID SEPARATION AND RECOVERY OF PATHOGENS FROM FOOD SAMPLES BY MICROFILTRATION ASSISTED COUNTERFLOW ELUTRIATION (MACE)

Final Rejection §103
Filed
Mar 05, 2021
Examiner
NGUYEN, BOI-LIEN THI
Art Unit
1779
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Pathotrak Inc.
OA Round
5 (Final)
25%
Grant Probability
At Risk
6-7
OA Rounds
3y 10m
To Grant
75%
With Interview

Examiner Intelligence

Grants only 25% of cases
25%
Career Allow Rate
13 granted / 52 resolved
-40.0% vs TC avg
Strong +50% interview lift
Without
With
+50.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 10m
Avg Prosecution
45 currently pending
Career history
97
Total Applications
across all art units

Statute-Specific Performance

§103
49.5%
+9.5% vs TC avg
§102
19.5%
-20.5% vs TC avg
§112
30.3%
-9.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 52 resolved cases

Office Action

§103
DETAILED ACTION This detailed action is in response to the amendments and arguments filed on 09/08/2025, and any subsequent filings. Notations “C_”, “L_” and “Pr_” are used to mean “column_”, “line_” and “paragraph_”. Claims 1, 4-9, 15-20, 24-25 and 28-29 are canceled. Claims 21-22 and 30-33 are pending. 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 . Response to Arguments Claim Rejections - 35 USC § 103 Claim 21 The Applicant argues that references Hedrick and Ladisch do not teach recovering a filtrate of the fluid from the one of more outlets of the housing and extracting the pathogen from the filtrate (pg. 6). This is unpersuasive because Hedrick teaches recovering a filtrate of the fluid from the one of more outlets of the housing (Hedrick, Fig. 6) and Ladisch teaches extracting the pathogen from the filtrate (Ladisch, [0010]). Furthermore, Hedrick teaches recovering a filtrate of the fluid from the one of more outlets of the housing (Hedrick, [0112], the cell composition is passed through filters to remove larger particles first, letting cells go through) and extracting the from the filtrate (Hedrick, [0132], further concentration). The Applicant argues that the screening member and microfiltration membrane of Hedrick are not arranged between the one or more inlets and the one or more outlets (pgs. 7-8). This is unpersuasive because the ports of Hedrick can be positioned in other regions as well (Hedrick, [0130]). The Applicant argues that the concentrated cells recovered from outlet port 31b of Hedrick is not a filtrate (pgs. 8-9). This is unpersuasive because Hedrick teaches recovering a filtrate of the fluid from the one of more outlets of the housing (Hedrick, [0112], the cell composition is passed through a first filter to remove larger particles first, letting cells go through). The Applicant argues that Ladisch does not teach or suggest recovering a filtrate of the fluid from the one or more outlets of the housing (pgs. 9-10). This is unpersuasive because Ladisch teaches recovering a filtrate of the fluid from the one or more outlets of the housing ([0159-0160], filtrate is concentrated and cells are present in the filtrate). Response to Amendment 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. The factual inquiries 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 21-22 and 30-33 are rejected under 35 U.S.C. 103 as being unpatentable over Hedrick (US20150152375A1, Jun. 4, 2015) in view of Ladisch (US20050244943A1, Nov. 3, 2005). The Applicant’s claims are directed towards a method. Regarding Claims 21-22 and 30-33, Hedrick teaches a method for separating pathogen from a test sample (abstract), comprising: flowing a fluid through a housing from one or more inlets of the housing to one or more outlets of the housing (Fig. 2, [0083], plurality of filters 36 and [0113], filter(s) housing), the fluid flowing through each of a screening member of the housing, the test sample, and a microfiltration membrane of the housing ([0130-0131]), wherein the screening member and the microfiltration membrane are arranged between the one or more inlets and the one or more outlets (Fig. 2, [0112]), wherein the screening member of the housing and the microfiltration membrane of the housing separate the housing into a first cavity formed below the screening member, a second cavity formed between the screening member and the microfiltration membrane, and a third cavity formed above the microfiltration membrane (Fig. 6), and wherein the test sample is positioned within the second cavity (Fig. 6, [0131]); recovering a filtrate of the fluid (Fig. 2, [0112], the cell composition is passed through a first filter to remove larger particles first, letting cells go through. [0115], through the second filter. Figs. 10-11, [0127], through the first and second filters) from the one or more outlets of the housing ([0113], first filter and second filter can be in one housing). Hedrick does not teach extracting the pathogen from the filtrate. Ladisch also relates to a method of separating pathogen ([0010]) from a test sample and, extracting the pathogen from the filtrate ([0159-0160], note that Whatman 113 filter paper has a pore size of 30 µm and Whatman 6 filter paper has a pore size of 3 µm). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the method of Hedrick can be used in a method of separating pathogen from a test sample and extracting the pathogen from the filtrate, as demonstrated by Ladisch, because both of the separators of Hedrick and Ladisch separate and concentrate biological samples, including tissue cells and blood (Hedrick, [0056] and Ladisch, [0021-0022]). Additional Disclosures Included: Claim 22: the pathogen comprises one or more of Salmonella (Ladisch, [0020]), E. coli O157H7, E. coli STEC, Listeria (Ladisch, [0020]), Campylobacter, Clostridium botulinum, Staphylococcus aureus (Ladisch, [0020]), Shigella (Ladisch, [0020]), Toxoplasma gondii, Vibrio vulnificus, and Norovirus. Claim 30: extracting the pathogen (see analysis of Claim 21) from the filtrate comprises recovering the pathogen from a concentrator membrane (Hedrick, Figs. 10-11, [0115] and [0120], third filter may be a hollow fiber filter which retains regenerative cells) arranged in fluid communication with the one or more outlets of the housing and configured to receive the filtrate (Hedrick, Figs. 10-11, [0127]). Claim 31: the fluid flows at an average velocity of about 1 mm/min to about 40 mm/min (flow liquid flows at about 10 mL/min (Hedrick, [0131]) and the filters 36a and 36b can have a surface area of 785 mm2 (Hedrick, [0130]), resulting in an average flow velocity of approximately 12.8 mm/min). Claim 32: the fluid flows through the housing at an average velocity of about 4 mm/min (the cell recovery membrane diameter is increased from 25 mm to 47 mm (Ladisch, [0147]) while the flow rate of organism-containing liquid is 5 mL/min (Ladisch, [0085]). This results in an average flow velocity of approximately 3 mm/min). Claim 33: the fluid flows through the housing at a volumetric flow rate of about 100 ml/hour to about 4 L/hour (saline may have a rate of 10 mL/min (Hedrick, [0131]), or 600 mL/hour when converted). 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 BOI-LIEN THI NGUYEN whose telephone number is (703)756-4613. The examiner can normally be reached Monday to Friday, 8 am to 6 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, Bobby Ramdhanie can be reached at (571) 270-3240. 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. /BOI-LIEN THI NGUYEN/Examiner, Art Unit 1779 /Bobby Ramdhanie/Supervisory Patent Examiner, Art Unit 1779
Read full office action

Prosecution Timeline

Mar 05, 2021
Application Filed
Dec 08, 2023
Response after Non-Final Action
Dec 18, 2023
Non-Final Rejection — §103
Mar 26, 2024
Response Filed
May 09, 2024
Final Rejection — §103
Jul 23, 2024
Interview Requested
Aug 02, 2024
Examiner Interview Summary
Aug 15, 2024
Request for Continued Examination
Aug 16, 2024
Response after Non-Final Action
Nov 27, 2024
Non-Final Rejection — §103
Feb 28, 2025
Non-Final Rejection — §103
Aug 21, 2025
Examiner Interview Summary
Sep 08, 2025
Response Filed
Nov 10, 2025
Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12459844
ULTRAPURE WATER SUPPLYING APPARATUS, SUBSTRATE PROCESSING SYSTEM INCLUDING THE SAME, AND PROCESSING SUBSTRATE METHOD USING THE SAME
2y 5m to grant Granted Nov 04, 2025
Patent 12415190
Collector Composition and Methods of Using Thereof
2y 5m to grant Granted Sep 16, 2025
Patent 12403412
METAL-ORGANIC FRAMEWORKS FOR THE REMOVAL OF UREMIC TOXINS
2y 5m to grant Granted Sep 02, 2025
Patent 12397090
DEVICES AND METHODS FOR NITROSYLATION OF BLOOD
2y 5m to grant Granted Aug 26, 2025
Patent 12337283
SPIRAL-WOUND FILTER MODULE EXHIBITING ALMOST NO HEAVY METAL LEACHING AND MANUFACTURING METHOD THEREOF
2y 5m to grant Granted Jun 24, 2025
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

6-7
Expected OA Rounds
25%
Grant Probability
75%
With Interview (+50.4%)
3y 10m
Median Time to Grant
High
PTA Risk
Based on 52 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month