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 .
Priority
Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 10/12/2023 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
Election/Restrictions
Applicant’s election without traverse of Group I drawn to a method of removing a histological stain from a histologically stained sample; and preparing said sample for a subsequent analysis method, comprising contacting the sample with various agents, including an acidic and an reducing agent in the reply filed on 10/20/2025 is acknowledged.
Claim 27 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)). Claims 1-4, 7-9, 11-14, 16-18, and 20-25 are pending and under exam.
Claim Interpretation
Optional embodiments are not given patentable weight as they are not required by the claim. See for example claims 2, 4, and 25.
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 1-4, 7-9, 11-14, 16-18, and 20-25 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 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 applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Regarding claims 1-4: The claims encompass a method of removing any histological stain from a sample, by
contacting the sample with any acidic reagent with a pH of 1.0 to 4.0 and
contacting the sample with any reducing agent with a pH from 8.0 to 10.0.
It is noted that the specification and examples are limited to Hematoxylin and Eosin (H&E stain). The disclosure does not describe or exemplify destaining of other classes of histological stains, including but not limited to silver impregnation stains, enzyme-based stains, lipid-partition stains, immunohistochemical chromogens, or fluorescent stains.
The specification provides no discussion of the chemical compatibility of the claimed destaining procedure with stains other than H&E, nor any guidance as to whether or how the claimed method would operate on such stains. Accordingly, the disclosure fails to demonstrate possession of a method for removing histological stains generally, as claimed.
As a second matter, the specification discloses only a specific acidic solution, not the full scope of claimed acidic agents.
The claims recite contacting the sample with an “acidic agent” having a pH from 1.0 to 4.0, which encompasses a broad genus of acidic reagents.
In contrast, the working examples disclose only a single specific acidic solution, namely hydrochloric acid in alcohol (e.g., 1% HCl in 70% alcohol). The specification neither describes the use of other acids, acid types, or acidic solutions, nor does it provide guidance indicating that other acidic agents would be suitable or interchangeable.
As a third matter, the specification discloses only a specific reducing agent, such as sodium borohydride. The examples of the application do not disclose other reducing agents nor do they provide support that the sodium borohydride can be easily replaced with other reducing agents. As such the data and the disclosure in the specification only support narrow subset of the reducing agents.
Thus, Applicants were not in possession of the full scope of the claimed invention at the time of filing of the instant invention. Claims 7-9, 11-14, 16-18 and 20-25 inherit the rejection.
Claims 1-4, 7-9, 11-14, 16-18, and 20-25 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.
Applicant's specification is found enabling for destaining H&E stain using treatment with hydrochloric acid alcohol solution and subsequent treatment with a sodium borohydride reducing agent treatment.
Applicant's specification is not found to be enabling for destaining any histological stain by contacting with any acidic agent, and any reducing agent treatment. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to carry out the method of the invention commensurate in scope with the current claims.
Analysis of whether a particular claim is supported by the disclosure in an application requires a determination of whether that disclosure, when filed, contained sufficient information regarding the subject matter of the claims as to enable one skilled in the pertinent art to make and use the claimed invention without undue or unreasonable experimentation. See Mineral Separation v. Hyde, 242 U.S. 261, 270 (1916). The key word is 'undue,' not experimentation.' " (Wands, 8 USPQ2d 1404). The factors to be considered in determining whether undue experimentation is required are summarized In re Wands 858 F.2d 731, 8 USPQ2nd 1400 (Fed. Cir, 1988). The factors to be considered in determining whether undue experimentation is required include: (1) the quantity of experimentation necessary, (2) the amount or direction or guidance presented, (3) the presence or absence of working examples, (4) the nature of the invention, (5) the state of the prior art, (6) the relative skill of those in the art, (7) the predictability or unpredictability of the art, and (8) the breadth of the claims. While all these factors are considered, a sufficient number are discussed below so as to create a prima facie case.
Applicants' claims are directed to a method of removing a stain. The breadth of the claims includes chromogenic and fluorescent stains. These stains are not limited to cyanin stains or PAS stains which are covalent stains which cannot be removed by acid-reducing agent treatment as claimed. (See Day et al, Abstract; See Manoj et al, p. 1, col. 1, first para; See PTO-892).
Further the claims are directed to use of any acid (claim 1), or sulfuric acid, nitric acid, hydrobromic acid, hydroiodic acid, sulfamic acid, perchloric acid as required by dependent claim 13. Use of acid to wash excess stain or destaining is well known in the art. However, it was well known in the art that “[s]trong inorganic acids are very harsh chemicals that can damage the soft-tissue structure as well as negatively affect cellular integrity, but on the other hand, strong acid usually takes less time to complete decalcification procedures so the strong acids can be used for the decalcification of highly mineralized cortical bone specimen.” (See Khangura, p. 464, col. 1 last para to col. 2, first para; See PTO-892).
Further the claims are directed to any and all reducing agent treatment. At the time of filing the application that sodium borohydride was the most commonly used reducing agent for histological purposes, especially for reducing autofluorescence. (See Davis et al Abstract).
The specification provides evaluation of fluorescence signal quality in multiplexed immunohistochemistry performed on tissue sections that were previously subjected to H&E staining, followed by various chemical treatments. Example 1 taught that the fluorescence quality improves when a tissue previously stained with H&E is treated with acid alcohol solution and sodium borohydride prior to IHC. Example 2 evaluated the comparison of hematoxylin stain removal under different reducing agent conditions.
At the time the invention was made it was known that several kinds of stain exist for various purposes. For example, fluorescent stain and chromogenic stains lipid soluble stains (Sudan Black), hematological stan (Giemsa Stain), collagen stain (Masson's Trichrome) among many others. (See Gurina et al; See PTO-892). The destaining procedure of H&E stain was well understood and documented and the use of acid alcohol, particularly was well documented. (See Trivalairat, p. 35, Section 2.2; See PTO-892). It was also known that harsh/strong acids were unfavorable as they were known to damage the architecture of tissues. If harsh acids were used, the time of exposure and the concentrations had to be determined according to the property of the acid. Further use of a reducing agent in destaining procedure was unknown in the field of histology. Therefore, there was a recognized level of unpredictability with regards to use of stain, and its particular destaining procedure.
Due to the lack of teachings in the art regarding all stains that can be destained using an acid and reducing agent, the nature of the acid, and the reducing agent, and the recognized unpredictability in the area of destaining a histological sample, a large amount of guidance and teachings would be necessary in order to be enabling for methods of such.
Guidance and teachings provided by Applicants in the instant specification is limited to disclosure that H&E stain can be destained using 1% HCl in 70% EtOH and 1% NaBH4 solution in water. (For example see [0147]-[0148]). The Examiner acknowledges that the Office does not require the presence of working examples to be present in the disclosure of the invention (see MPEP §2164.02). However, in light of the state of the art, discussed above, which recognizes a high level of unpredictability in the field of histology, and limited teachings with regards to destaining tissues with acid and reducing agents, the Office would require appropriate disclosure to support the methods of claims 1-4, 7-9, 11-14, 16-18, and 20-25. The amount of guidance or direction needed to enable the invention is inversely related to the amount of knowledge in the state of the art as well as the predictability in the art. In re Fisher, 427 F.2d 833, 839, 166 USPQ 18, 24 (CCPA 1970). Thus, due to the high level of unpredictability in the art, the current specification would have to provide greater amounts of teachings and guidance directed to methods of carrying out the claimed invention.
Therefore, due to the sum of all the aforementioned factors, one of ordinary skill in the art, at the time the invention was made, would not expect success carrying out the claimed method of removing stain from a histological sample. Given that the art fails to recognize and Applicant has failed to demonstrate the full scope of the claimed method, the skilled artisan would be faced with the impermissible burden of undue experimentation in order to practice the claimed invention using any species of stem cell. Accordingly, claims 1-4, 7-9, 11-14, 16-18, and 20-25 are deemed properly rejected.
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 1-4, 7-9, 11-14, 16-18, and 20-25 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as failing to set forth 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 18 recites that the reducing agent is selected from sodium borohydride, sodium cyanoborohydride, potassium bromate, sodium sulfite, sodium dithionite, sodium thiosulfate, sodium bisulfite, sodium triethylborohydride, and sodium triacetoxyborohydride, or a combination thereof. However, it is submitted that potassium bromate is a strong oxidizing agent. (See Kurokawa et al Abstract, See PTO-892). The metes and bounds of this claim is unclear.
Regarding claims 1-4, 7-9, 11-14, 16-18, and 20-25:
Example 1 and Figures 1-8 are directed to fluorescence images from multiplexed IHC experiments. The fissures are directed to fluorescence signal intensity and background fluorescence and may relate to signal to noise ratio. However, they do not directly show the presence or absence of chromogenic histological stains which are evaluated under brightfield microscopy. Example 1 shows fluorescence signal improves when tissues are treated with acid and sodium borohydride. The examples do not establish that histological stain is actually removed, as opposed to rendered non-fluorescent or less optically interfering.
Only Figure 9 in Example 2 includes brightfield microscopy images. However, these images are taken with treatment of both acidic agent and varying concentrations of reducing agents. It is not clear if the acidic agent treatment would have been sufficient to destain the H&E stain.
In view of the examples and figures, the specification does not clearly establish that the combination of acidic agent treatment and reducing agent treatment results in removal of histological stain, as opposed to quenching of autofluorescence or interference with fluorescence detection. The term “removing the histological stain” therefore lacks a clear objective boundary and renders the scope of the claim indefinite.
Conclusion
Claims 1-4, 7-9, 11-14, 16-18, 20-25 and 27 appear free of art, but lack written description or enablement and definiteness.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAGAMYA VIJAYARAGHAVAN whose telephone number is (703)756-5934. The examiner can normally be reached 9:00a-5:00p.
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, Christopher M. Babic can be reached at 571-272-8507. 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.
/JAGAMYA NMN VIJAYARAGHAVAN/ Examiner, Art Unit 1633
/EVELYN Y PYLA/ Primary Examiner, Art Unit 1633