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 .
Election/Restrictions
Applicant's election with traverse of Group I, claims 52-53, 60, and 62-66, alongside GSH in claim 3 and GSS in claim 9, in the reply filed on 23 February 2026 is acknowledged. The traversal is on the ground(s) that the claims as filed relate to one group of inventions involving the special technical feature of creation of oxidative stress resistant strains of mammalian host cells by exposure to hydrogen peroxide and the use of these strains in the production of e.g., antibodies.
This argument is not persuasive because the feature of using the strains in the production of antibodies is not a common feature. For example, Group II (i.e., claims 52-53, 60, and 62-66) is drawn towards a method of producing a mammalian host cell and does not recite the production of antibodies, as required by the hydrogen peroxide evolved host cell of Group I (i.e., claims 1-3, 5, 7, 9, and 11-15) or the hydrogen peroxide evolved host cell of Group III (i.e., claim 68). Thus, the alleged shared special technical feature is not shared by all three Groups identified in the previously pending restriction requirement as the method of Group II is strictly drawn towards a method of creating the products of Groups I and III and does not recite the production of antibodies.
Applicant alleges that the international application from which the current application stems from recognized unity amount the groups.
This is not found persuasive because Applicant has not provided any specific arguments pertaining to the art cited in the Restriction/Election requirement filed 23 December 2025. Applicant has not provided any arguments pertaining to how the technical feature makes a contribution over the art cited in the Restriction/Election requirement filed 23 December 2025.
Accordingly, the requirement is still deemed proper and is therefore made FINAL.
Claims 1-3, 5, 7, 9, 11-15, and 68 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 23 February 2026.
Applicant is reminded that upon the cancelation of claims to a non-elected invention, the inventorship must be corrected in compliance with 37 CFR 1.48(a) if one or more of the currently named inventors is no longer an inventor of at least one claim remaining in the application. A request to correct inventorship under 37 CFR 1.48(a) must be accompanied by an application data sheet in accordance with 37 CFR 1.76 that identifies each inventor by his or her legal name and by the processing fee required under 37 CFR 1.17(i).
Claim Objections
Claim 53 is objected to because of the following informalities: part (e) of the claim recites “H2O2and”. The phrase is grammatically incorrect. Examiner suggest amending the phrase to recite “H2O2 and”. Appropriate correction is required.
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 52-53, 60, and 62-66 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.
Regarding claims 52-53, 60, and 62-66, the term “about” in the claims is a relative term which renders the claim indefinite. The term “about” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention.
The specification does teach that “the term ‘about’ refers to variation in the numerical quantity that can occur, for example, through typical measuring and handling procedures used for making compounds, compositions, concentrates or formulations; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of starting materials or ingredients used to carry out the methods, and other similar considerations. The term ‘about’ also encompasses amounts that differ due to aging of a formulation with a particular initial concentration or mixture, and amounts that differ due to mixing or processing a formulation with a particular initial concentration or mixture” (Instant specification; pg. 14-15).
Therefore, it is unclear what amount of claimed H2O2 (see Claims 52, 53, 62, and 65), claimed minutes (see Claims 53 and 63), claimed viability (see Claim 60), claim repeated method steps (see Claim 64), or claimed L-glutamine (see Claim 66) is encompassed by the claim language because the definition of the term “about” in the specification encompasses variations in numerical values that are determinant on who is performing the method and how much “inadvertent error” is performed in the method. For example, is the term “about” intended to encompass claimed variations that are so small or large that one of ordinary skill in the art would consider the concentration inadvertent error? Further, the term “about” is not defined in the specification to be a specific percent variation from a particular claimed value.
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 52-53, 60, and 62-66 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, while being enabling for a method of producing an evolved population of CHO cells with increased resistance to cellular stress, the method comprising multiple rounds of culturing the population of cells in the presence of four exposures of 14 mM H2O2, one round of 18.5 mM H2O2, and one rounds of 37 mM H2O2 and allowing the cells to recover until the cells can survive in the presence of 37 mM H2O2, does not reasonably provide enablement for utilizing “about 5 mM to about 20 mM” or “about 10 mM to about 15 mM H2O2”, as defined by the instant specification, in order to produce an evolved population of any mammalian cell that can survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to use the invention commensurate in scope with these claims.
Factors to be considered in determining whether a disclosure meets the enablement requirement of 35 U.S.C. 112, first paragraph, have been described by the court in In re Wands, 8 USPQ2d 1400 (Fed. Cir. 1988). Wands states, on page 1404:
Factors to be considered in determining whether a disclosure would require undue experimentation have been summarized by the board in Ex part Forman. They include (1 the quantity of experimentation necessary, (2) the amount of 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 these in the art, (7) the predictability or unpredictability of the art, and (8) the breadth of the claims.
Regarding claim 52, the claim requires producing an evolved population of a genera of host cells via the administration of “about 5 mM to about 20 mM” or “about 10 mM to about 15 mM H2O2”, as defined by the instant specification, in order to produce an evolved population of any mammalian cell that can survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification.
The claims are not enabled for the production of any mammalian cell that can survive in the presence of the claimed H2O2 concentrations.
Nature of the Invention
Regarding claim 52, the nature of the invention is a method of generating H2O2 resistant cells that requires cell survival via the exposure of the cells to something that is inherently toxic and mutagenic: H2O2. Further, the claimed amount of H2O2 that the cells are required to be exposed to and subsequently survive in is considered high.
Breadth of the Claims
Regarding the claims, it is noted that the term “mammalian host cell” encompasses, but is not limited to, Chinese Hamster Ovary (CHO), baby hamster kidney (BHK), murine myeloma (NSO or SP2), or rat myeloma (YB2/0) cells (pg. 15-16). Therefore, the clams are drawn towards the production of any mammalian cell that can survive in the presence of the claimed H2O2 ranges.
State of the Art/Predictability of the Art
It is well established in the prior art that there are specific CHO host cells that could be introduced to hydrogen peroxide in order to generate an evolved mammalian host cell. However, the prior art further teaches that the mammalian host cells comprise a specific structure and that very specific concentrations of hydrogen peroxide must be introduced to the cells in order to generate a population of evolved mammalian host cells.
Fairbrass (Engineering Oxidative Stress Resistance in CHO Cell Factories. Diss. University of Sheffield, 2016) is directed towards a thesis concerned with engineering oxidative stress resistant in CHO cell factories (pg. 6). Fairbrass teaches a method of directed evolution of host CHO cell lines (i.e., a method of producing an evolved population of mammalian host cells) comprising introducing a starting concentration of 250 µM of H2O2 to a CHO cell line wherein fresh H2O2 was introduced at each subculture (passage) every 3 days (pg. 132). Fairbrass teaches that once cells were deemed to have recovered with a Percentage Viability above 80%, H2O2 concentration was doubled (pg. 132). Fairbrass teaches that a total of 130 generations of increasing H2O2 concentrations were added to the cell culture until the final concentration of H2O2 was 2mM and the CHO cells that were able to grow in the presence of the H2O2 were banked (pg. 132).
Further, Nakamura ("Micromolar concentrations of hydrogen peroxide induce oxidative DNA lesions more efficiently than millimolar concentrations in mammalian cells." Nucleic acids research 31.6 (2003): 1790-1795) is directed towards a review study concerned with how micromolar concentrations of hydrogen peroxide are toxic to mammalian cells (Abstract). Nakamura teaches that repeated exposure of HeLa cells (i.e., mammalian cells) to concentrations as low as 0.06 mM H2O2 is cytotoxic to the cells (pg. 1792).
Therefore, the closest prior art concerned with the evolution of mammalian cells via the introduction of H2O2 demonstrates that it would have been unpredictable to perform the method as claimed in order to generate mammalian host cells that have the claimed function. Further, although Fairbrass does provide evidence that utilizing specific concentrations of H2O2 to produce an evolved line of CHO cells that could survive in the presence of a specific concentration of H2O2, Fairbrass does not provide evidenced that any mammalian host cell, not limited by structure, could be subjected to “about 5 mM to about 20 mM” or “about 10 mM to about 15 mM H2O2”, as defined by the instant specification, in order to produce an evolved population of any mammalian cell that can survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification.
Even if, assuming arguendo, the claims are intended to be limited to the specific numerical ranges recited, the prior art nonetheless provides evidence of the unpredictability of performing the claimed method with the claimed concentrations because the prior art only teaches producing specific mammalian host cells that were resistant to a much smaller amount of H2O2 via the exposure of the host cells to much smaller amounts of H2O2 than what is currently claimed. Accordingly, the prior art teaches that performing the method as claimed with any mammalian cell in order to generate host cells with the claimed function is unpredictable.
Amount of Direction Provided by the Inventor/Existence of Working Examples
Regarding the amount of direction provided by the instant specification, the mere ability to culture a single type of mammalian cell (i.e., CHO cells) in the presence of four exposures of 14 mM H2O2, one round of 18.5 mM H2O2, and one rounds of 37 mM H2O2 and allowing the cells to recover until the cells can survive in the presence of 37 mM H2O2 (pg. 48-49; see FIG. 1A), is not representative of the ability to predictably use the invention as claimed because it fails to disclose how to utilize any mammalian cell in the claimed method. In addition, the specification, as filed, fails to provide any particular direction or guidance which resolves the known unpredictability in the art associated with culturing any mammalian cell in the presence of “about 5 mM to about 20 mM” or “about 10 mM to about 15 mM H2O2”, as defined by the instant specification, in order to produce an evolved population of any mammalian cell that can survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification.
Relative Skill of the Ordinary Artisan/Amount of Experimentation Required
With regard to the claims, the skill of those in the relative art is high, but still, given the
state and unpredictability of the art, undue experimentation would be required to determine if
any mammalian cell could be utilized in the claimed method in order to generate a host cell that is resistant to the claimed H2O2 ranges. For example, to even select a suitable mammalian host cell, screening multiple cell lines and determining their baseline H2O2 resistance would be required. Following the selection of a single suitable mammalian host cell, extensive trail-and-error of different amounts of H2O2 over many generations of the cells would need to be performed in order to generate the claimed H2O2 resistant cells. It would need to be determined whether the increase in H2O2 would need to be linear or adaptive based on the cell survival and whether to escalate the amount of H2O2 or repeat an exposure at the same level of H2O2 after each cycle of H2O2 exposure. The method would need to be restarted and repeated after the failure of a culture in order to validate the maximum amount of H2O2 the mammalian host cells can survive in. All of these method steps would need to be performed for each individual species of claimed mammalian host cell. Thus, the amount of experimentation required is enormous. Therefore, performing the method as claimed wherein the mammalian host cell is any mammalian cell and the claimed ranges are not specific cannot be predictably accomplished, as presently claimed.
Thus, the claims are not enabled commensurate in scope with the claimed invention.
Regarding claims 53, 60, and 62-66, as the claims are ultimately dependent on claim 52 and do not rectify the 35 USC 112(a) enablement rejection above, the claims are also rejected under 35 USC 112(a).
Claims 52-53, 60, and 62-66 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 claim 1, the claim is broadly drawn towards a method of producing an evolved population of mammalian host cells via the culturing of the cells in the presence of “about 5 mM to about 20 mM” or “about 10 mM to about 15 mM H2O2”, as defined by the instant specification, in order to produce an evolved population of any mammalian cell that can survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification.
Accordingly, the claim is interpreted as claiming a genus mammalian cells that have the function of being able to survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification. The claim requires the provision a genus of mammalian cells defined solely by function.
The instant specification does not provide support for the use of a genus of mammalian host cells that can perform the claimed function, and the closest prior art provides evidence that mammalian host cells must comprise a specific structure in order to perform the claimed function and that utilizing any mammalian host cell in the claimed method such that the host cells can survive in the claimed ranges of hydrogen peroxide, is unpredictable.
The MPEP lists factors that can be used to determine if sufficient evidence of possession has been furnished in the disclosure of the application. These include "level of skill and knowledge in the art, partial structure, physical and/or chemical properties, functional characteristics alone or coupled with a known or disclosed correlation between structure and function, and the method of making the claimed invention. Disclosure of any combination of such identifying characteristics that distinguish the claimed invention from other materials and would leave one of skill in the art to the conclusion that the applicant was in possession of the claimed species is sufficient." MPEP 2163. A claimed genus may be satisfied through sufficient descriptions of a representative number of species or disclosure of relevant, identifying characteristics such as functional characteristics coupled with known or disclosed correlation between function and structure. MPEP 2163(3)a(II). The number of species that describe the genus must be adequate to describe the entire genus; if there is substantial variability, a large number of species must be described.
The analysis for adequate written description considers (a) actual reduction to practice, (b) disclosure of drawings or structural chemical formulas, (c) sufficient relevant identifying characteristics in the way of complete/partial structure or physical and/or chemical properties or functional characteristics when coupled with known or disclosed correlation with structure, and (d) representative number of samples.
As the claims currently recite, as described above, the claim is directed towards a method of producing a genera of evolved populations of mammalian host cells via the culturing of the cells in the presence of “about 5 mM to about 20 mM” or “about 10 mM to about 15 mM H2O2”, as defined by the instant specification, in order to produce an evolved population of any mammalian cell that can survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification. While claiming a genus of structures (i.e., mammalian host cells) by a function (i.e., the ability to survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification) is not prohibited, there must be a sufficient structure-function relationship described in the specification such that the claimed genus was represented by a representative number of species or the teachings of the specification, or, the prior art can be used to support a well-known structure-function relationship.
In the instant case, the instant specification does not provide support that the broadly claimed mammalian host cells were able to survive the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification, as claimed. Further, the prior art demonstrates that the use of mammalian host cells and their ability to perform the claimed function is determinant on very specific method steps and that utilizing any mammalian cell to perform the claimed function is unpredictable.
Working Examples
With regard to working examples, the specification provides little evidence on the possession of a sufficient number of species which are encompassed by the entirety of the claimed genus.
MPEP 2163 teaches that “for some arts, there is an inverse correlation between the level of skill and knowledge in the art and the specificity of disclosure necessary to satisfy the written description requirement. Information which is well known in the art need not be described in detail in the specification. See, e.g., Hybritech, Inc. v. Monoclonal Antibodies, Inc., 802 F.2d 1367, 1379-80, 231 USPQ 81, 90 (Fed. Cir. 1986). However, sufficient information must be provided to show that the inventor had possession of the invention as claimed [emphasis added].”
In the instant case, the instant specification does provide support for the evolution of a singular species of mammalian host cells, CHO cells, via the culturing of the CHO cells in the presence of four exposures of 14 mM H2O2, one round of 18.5 mM H2O2, and one rounds of 37 mM H2O2 and allowing the cells to recover until the cells can survive in the presence of 37 mM H2O2 (pg. 48-49; see FIG. 1A).
However, when taken as a whole, the single species of CHO host cells present in the specification is not representative of the claimed genus as a whole because the claimed genus broadly encompasses any mammalian cell that can performed the claimed function of surviving in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification. Therefore, the instantly claimed genus of mammalian host cells present in claim 52 is not adequately described in the specification as being capable of surviving in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification.
Thus, the instant specification does not provide written description for the entirety of the claimed method comprising producing an evolved population of any mammalian host cell via the culturing of the cells in the presence of “about 5 mM to about 20 mM” or “about 10 mM to about 15 mM H2O2”, as defined by the instant specification, in order to produce an evolved population of any mammalian cell that can survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification (see Claim 52).
Prior Art
Regarding the state of the prior art, the closest prior art demonstrates that the mammalian host cells produced by the claimed method must be of a specific structure in order to perform the claimed function.
Fairbrass (Engineering Oxidative Stress Resistance in CHO Cell Factories. Diss. University of Sheffield, 2016) is directed towards a thesis concerned with engineering oxidative stress resistant in CHO cell factories (pg. 6). Fairbrass teaches a method of directed evolution of host CHO cell lines (i.e., a method of producing an evolved population of mammalian host cells) comprising introducing a starting concentration of 250 µM of H2O2 to a CHO cell line wherein fresh H2O2 was introduced at each subculture (passage) every 3 days (pg. 132). Fairbrass teaches that once cells were deemed to have recovered with a Percentage Viability above 80%, H2O2 concentration was doubled (pg. 132). Fairbrass teaches that a total of 130 generations of increasing H2O2 concentrations were added to the cell culture until the final concentration of H2O2 was 2mM and the CHO cells that were able to grow in the presence of the H2O2 were banked (pg. 132).
Further, Thanan ("Development and characterization of a hydrogen peroxide-resistant cholangiocyte cell line: A novel model of oxidative stress-related cholangiocarcinoma genesis." Biochemical and biophysical research communications 464.1 (2015): 182-188) is directed towards a study concerned with the generation of a hydrogen peroxide-resistant cholangiocyte cell line (Abstract). Thanan teaches that human MMNK1 cells can be repeatedly administered chronic treatments of 25 μM of H2O2 until the cells showed H2O2-resistant properties including increasing the expression of the anti-oxidant genes catalase (CAT), superoxide dismutase-1 (SOD1), superoxide dismutase-2 (SOD2), and superoxide dismutase-3 (SOD3) and the enzyme activities of CAT and intracellular SODs (Abstract). Thanan teaches that the MMNK1 cells were resistant to various concentrations of H2O2 (i.e., up to at least 300 μM of H2O2), where at least 50% of the cells survived the exposure (pg. 184; see Fig. 1).
Therefore, the prior art provides evidence that only specific mammalian cells can be cultured in the presence of “about 5 mM to about 20 mM” or “about 10 mM to about 15 mM H2O2”, as defined by the instant specification, in order to produce a specific evolved population mammalian cell that can survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification. Because the claims encompasses H2O2 values that are inclusive of values generated by “inadvertent error”, the broadest reasonable interpretation of the claims encompasses values of H2O2 that are so low that one of ordinary skill in the art would in fact label the low value as an “inadvertent error” generated by a mistake in methods of measuring the claimed H2O2. Further, because the instant specification does not define “about” as a particular numerical variation from a claimed value, it is reasonable to interpret the claimed ranges as being inclusive of the amounts of H2O2 described in the Fairbrass and Thanan references.
Thus, the prior art teaches that there are species of mammalian cells not described in the instant specification that could be cultured in the presence of “about 5 mM to about 20 mM” or “about 10 mM to about 15 mM H2O2”, as defined by the instant specification, in order to produce an evolved population of a specific mammalian cell that can survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification.
Even if, assuming arguendo, the claims are intended to be limited to the specific numerical ranges recited, the prior art nonetheless provides evidence of the unpredictability of performing the claimed method with the claimed concentrations because the prior art only teaches producing specific mammalian host cells that were resistant to a much smaller amount of H2O2 via the exposure of the host cells to much smaller amounts of H2O2 than what is currently claimed. Accordingly, the prior art teaches that performing the method as claimed with any mammalian cell in order to generate host cells with the claimed function is unpredictable.
Conclusion
The specification does not identify a representative number of species of the broadly claimed mammalian host cells that possess the claimed function of surviving in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification. Further, the prior art shows that prior to the effective filing date of the claimed invention that determining the ability for a specific mammalian cell to survive in the presence of “about 20 mM to about 40 mM H2O2”, as defined by the instant specification, is structure-dependent and that it is unpredictable to utilize any mammalian host cell, not limited by structure, to perform the claimed function.
Therefore, a person of ordinary skill in the art would not have concluded that Applicant was in possession of the invention as claimed. Thus, claim 52 is rejected under 35 U.S.C. 112(a).
Regarding claims 53, 60, and 62-66, as the claims are ultimately dependent on claim 52 and do not rectify the 35 USC 112(a) rejection above, the claims are also rejected under 35 USC 112(a).
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claim(s) 52-53, 60, and 62-66 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Fairbrass (Engineering Oxidative Stress Resistance in CHO Cell Factories. Diss. University of Sheffield, 2016).
Regarding claim 52, the claimed range of “about 5 mM to about 20 mM of […] H2O2” is interpreted as encompassing 250 µM of H2O2 because, as defined by the specification, the term “about” encompasses variation in the numerical quantity that can occur through inadvertent error (Instant specification; pg. 14-15). Further, the claimed range of “about 20 mM to about 40 mM” is interpreted as encompassing 2 mM of H2O2 because, as defined by the specification, the term “about” encompasses variation in the numerical quantity that can occur through inadvertent error (Instant specification; pg. 14-15). Because the claims encompasses H2O2 values that are inclusive of values generated by “inadvertent error”, the broadest reasonable interpretation of the claims encompasses values of H2O2 that are so low that one of ordinary skill in the art would in fact label the low value as an “inadvertent error” generated by a mistake in methods of measuring the claimed H2O2. Further, because the instant specification does not define “about” as a particular numerical variation from a claimed value, it is reasonable to interpret the claimed ranges as being inclusive of 250 µM of H2O2 and 2 mM of H2O2.
Fairbrass is directed towards a thesis concerned with engineering oxidative stress resistant in CHO cell factories (pg. 6). Fairbrass teaches a method of directed evolution of host CHO cell lines (i.e., a method of producing an evolved population of mammalian host cells) comprising introducing a starting concentration of 250 µM of H2O2 to a CHO cell line wherein fresh H2O2 was introduced at each subculture (passage) every 3 days (pg. 132). Fairbrass teaches that once cells were deemed to have recovered with a Percentage Viability above 80%, H2O2 concentration was doubled (pg. 132). Fairbrass teaches that a total of 130 generations of increasing H2O2 concentrations were added to the cell culture until the final concentration of H2O2 was 2mM and the CHO cells that were able to grow in the presence of the H2O2 were banked (pg. 132).
Regarding claim 53, Fairbrass teaches (a) providing a host CHO cell line (i.e., a population of cells) and (b) culturing the cells in media (pg. 132). Fairbrass teaches that (c) the cells were contacted with a starting concentration of 250 µM of H2O2 (i.e., about 5 mM H2O2 as defined by the Instant Specification) wherein fresh H2O2 was introduced at each subculture every 3 days (i.e., about 30 minutes to about 120 minutes as defined by the Instant Specification) (pg. 132). Fairbrass teaches that (d) cells were cryopreserved before each concentration increase in order to create cell banks (pg. 47-48). Fairbrass teaches that post revival of banked cell lines, H2O2 was not included in cell culture medium (pg. 47-48). Fairbrass teaches that the banked cell lines were subcultured in H2O2 (pg. 47-48). Fairbrass teaches that once cells were deemed to have recovered with a Percentage Viability above 80%, H2O2 concentration was doubled (pg. 132). Fairbrass teaches (e) repeating the culturing cycle until the cells could survive in 2mM H2O2 for 2 days (i.e., a concentration of about 20 mm and a time range of about 30 minutes to about 1 hour as defined by the Instant Specification) as measured by a viability analyzer (pg. 47-49, 132).
Regarding claim 60, Fairbrass teaches that once cells were deemed to have recovered with a Percentage Viability above 80%, H2O2 concentration was doubled (pg. 132).
Regarding claim 62, Fairbrass teaches that a total of 130 generations of increasing H2O2 concentrations were added to the cell culture until the final concentration of H2O2 was 2mM (i.e., about 10 mM as defined by the Instant Specification) and the CHO cells that were able to grow in the presence of the H2O2 were banked (pg. 132).
Regarding claim 63, Fairbrass teaches that the cells were contacted with a starting concentration of 250 µM of H2O2 (i.e., about 5 mM H2O2 as defined by the Instant Specification) wherein fresh H2O2 was introduced at each subculture every 3 days (i.e., about 30 minutes to about 120 minutes as defined by the Instant Specification) (pg. 132).
Regarding claim 64, Fairbrass teaches that a total of 130 generations of increasing H2O2 concentrations were added to the cell culture until the final concentration of H2O2 was 2mM and the CHO cells that were able to grow in the presence of the H2O2 were banked (pg. 132).
Regarding claim 65, Fairbrass teaches that it is common practice to restrict the number of host cell subcultures to less than 20 subcultures that comprise a total of 60-70 population doublings (pg. 30). Fairbrass teaches that the CHO evolved host cells were not subcultured more than 20 times during the method of evolving the cells before they could survive in 2 mM H2O2 (i.e., the cells could survive when contacted with about 20 mM H2O2 as defined by the Instant Specification after at least about 60 population doublings as defined by the Instant Specification) (pg. 48, 132).
Regarding claim 66, Fairbrass teaches that subcultures comprising the evolved CHO cells comprised 8 mM L-Glutamine (pg. 37).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KYLE T REGA whose telephone number is (571)272-2073. The examiner can normally be reached M-R 8:30-4:30, every other F 8:30-4:30 (EDT/EST).
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/KYLE T REGA/Examiner, Art Unit 1636
/NEIL P HAMMELL/Supervisory Patent Examiner, Art Unit 1636
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