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 .
Detailed Action
This office action is a response to applicant’s communication submitted April 16, 2026, wherein claim 1 is amended and claims 9 and 11 are canceled. This application is a national stage application of PCT/JP2021/019014, filed May 19, 2021, which claims priority to foreign application JP2020-090405, filed May 25, 2020.
Claims 1-5, 8, and 10 are pending in this application.
Claims 1-5, 8, and 10 as amended are examined on the merits herein.
Withdrawn Rejections
Applicant’s amendment, submitted April 15, 2026, with respect to the rejection of claims 1-5 and 8-11 under 35 USC 103 for being obvious over Callahan et al. in view of Srinvasan et al., has been fully considered and found to be persuasive to remove the rejection as the claims have been amended to narrow the scope of washing steps that can be used. Therefore the rejection is withdrawn.
Applicant’s amendment, submitted April 16, 2027, with respect to the rejection of claims 1-5, 8, and 10 under 35 USC 102(a)(1) for being anticipated by Oommen et al., has been fully considered and found to be persuasive to remove the rejection as claim 1 has been amended to require that the metal cation have a valence of two or greater. Therefore the rejection is withdrawn.
Applicant’s amendment, submitted April 16, 2027, with respect to the rejection of claims 1-5, 8, and 10 under 35 USC 103 for being obvious over Oommen et al., has been fully considered and found to be persuasive to remove the rejection as claim 1 has been amended to require that the metal cation have a valence of two or greater. Therefore the rejection is withdrawn.
Applicant’s amendment, submitted April 16, 2027, with respect to the rejection of claims 1-5, 8, and 10 under 35 USC 103 for being obvious over Michelsen et al., has been fully considered and found to be persuasive to remove the rejection as claim 1 has been amended to require that the metal cation have a valence of two or greater. Therefore the rejection is withdrawn.
The rejection of claims 1-5 and 8-11 for claiming the same invention as claims 1-4 of US patent 12264311 in view of Callahan et al. in view of Srinivasan et al., is withdrawn in view of the terminal disclaimer submitted April 16, 2026.
Applicant’s amendment necessitates the following new grounds of rejection:
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 8 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. This claim depends from claim 1 and further defines the metal cation as being selected from a number of potions including an alkali metal ion. However, as presently amended claim 1 requires that the metal ion have a valence of at least two, which rules out all alkali metal ions. Therefore claim 8 fails to include all of the limitations of base claim 1. Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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.
Claims 1-5, 8, and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Callahan et al. (US pre-grant publication 2019/0071665, of record in previous action) in view of Oommen et al. (US pre-grant publication 2018/0105809, of record in previous action)
Independent claim 1 claims a process for purifying a nucleic acid comprising steps of combining the nucleic acid with a solution containing a metal cation, contacting the nucleic acid further with an anionic adsorbent, washing the adsorbent and bound nucleic acid with a solution having pH 5.0 or less, and then recovering the nucleic acid by contacting the bound nucleic acid with a solution having pH 6.0 or more. Furthermore the wash solution is defined as either water (i.e. unbuffered water adjusted to pH 5 or less by addition of an acid) potassium chloride, glycine, citrate, or phosphate. Dependent claims 2-5 further define elements of the recovery solution. Dependent claim 8 further defines the composition of the extraction or binding solution. Claim 10 defines the anionic adsorbent as silica.
Callahan et al. discloses methods for the isolation of RNA and protein from a sample comprising contacting the sample with a silica-containing surface, which binds RNA and proteins from the sample. (p. 1 paragraphs 6-7) In some embodiments the sample bound to the support has a pH of less than 4 and a chloride salt at a concentration of greater than 2M. (p. 1 paragraph 8) The RNA can then be eluted with RNAse free water or TE buffer, which is an elution buffer having a pH of greater than 6. (p. 1 paragraph 9) In some embodiments the chloride salt is selected from a number of different options including alkali metals such as sodium, potassium, or lithium, or alkaline earth metals having a valence of 2, for example magnesium or calcium. (p. 1 paragraph 13)
Regarding claim 2, RNAse-free water and TE buffer are both considered to be solutions that do not inhibit nucleic acid amplification. Regarding claim 3, TE buffer is a buffer. Regarding claim 5, in the absence of any further definition, the water and buffer used in the elution buffer can be considered to be amplification reagents. Regarding claims 10 and 11, p. 2 paragraph 20 describes the silica surface as glass fibers or silica-coated magnetic beads.
In one embodiment the elution described by Callahan is carried out in a solution of NaOH and 50 mM TRIS at pH 8.0, (p. 5 paragraph 85) which meets the limitations of present claim 1 and dependent claims 2-4. Because the recovered nucleic acids can then be used for PCR, they are reasonably considered to be free of substances that interfere with PCR. Regarding claim 5, the term “nucleic acid amplification reagent” is not defined in the claims or specification, it is seen as including any reagent that could be present in an amplification reaction, including for example the base and buffer present in the extraction solution.
The disclosure of Callahan et al. differs from that of the present claims in that it does not disclose an acidic wash buffer. However, Oommen et al. discloses a method for extracting nucleic acids from a sample comprising adding a lysis buffer to a sample followed by a binding buffer, contacting the resulting solution with a portable nucleic acid extraction apparatus, washing the apparatus with a washing buffer, and eluting nucleic acids from the apparatus with an elution buffer. (p. 1 paragraphs 5-6) The tip of said apparatus is configured to bind nucleic acids. (p. 1 paragraph 19) The apparatus including the tip is preferably made of materials including polystyrene, glass, and silica. (p. 2 paragraphs 25-26) In a particular embodiment the nucleic acid binding portion of the apparatus is a fiber, such as a silica fiber. (p. 2 paragraphs 28-29) In a preferred embodiment the binding buffer contains sodium hypochlorite, which contains an alkali metal cation as recited in present claims 1 and 8, and glycine-HCl at pH 2-4, the wash buffer contains glycine-HCl, and the elution buffer contains TRIS-HCl at pH 8.8. (p. 2 paragraph 34) The wash buffer is further described as containing a salt that can include potassium chloride, as well as glycine-HCl as a buffer. (p. 5 paragraph 52)
It would have been obvious to one of ordinary skill in the art at the time of the invention to use an acidic wash solution such as the glycine-HCl buffer described by Oommen et al. in a nucleic acid isolation method as described by Callahan et al. One of ordinary skill in the art would have seen the disclosure of Callahan as being fairly generic as to what wash steps can be used, and would have reasonably expected that the acidic wash steps described by Oommen et al. would have worked in the protocol of Callahan et al. as well.
For these reasons the invention taken as a whole is prima facie obvious.
Claims 1-5, 8, and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Callahan et al. (US pre-grant publication 2019/0071665, of record in previous action) in view of Michelsen et al. (US patent 6355792, of record in previous action)
Independent claim 1 claims a process for purifying a nucleic acid comprising steps of combining the nucleic acid with a solution containing a metal cation, contacting the nucleic acid further with an anionic adsorbent, washing the adsorbent and bound nucleic acid with a solution having pH 5.0 or less, and then recovering the nucleic acid by contacting the bound nucleic acid with a solution having pH 6.0 or more. Furthermore the wash solution is defined as either water (i.e. unbuffered water adjusted to pH 5 or less by addition of an acid) potassium chloride, glycine, citrate, or phosphate. Dependent claims 2-5 further define elements of the recovery solution. Dependent claims 8-9 further define the composition of the extraction or binding solution. Claims 10 and 11 define the anionic adsorbent as silica.
Callahan et al. discloses methods for the isolation of RNA and protein from a sample comprising contacting the sample with a silica-containing surface, which binds RNA and proteins from the sample. (p. 1 paragraphs 6-7) In some embodiments the sample bound to the support has a pH of less than 4 and a chloride salt at a concentration of greater than 2M. (p. 1 paragraph 8) The RNA can then be eluted with RNAse free water or TE buffer, which is an elution buffer having a pH of greater than 6. (p. 1 paragraph 9) In some embodiments the chloride salt is selected from a number of different options including alkali metals such as sodium, potassium, or lithium, or alkaline earth metals having a valence of 2, for example magnesium or calcium. (p. 1 paragraph 13)
Regarding claim 2, RNAse-free water and TE buffer are both considered to be solutions that do not inhibit nucleic acid amplification. Regarding claim 3, TE buffer is a buffer. Regarding claim 5, in the absence of any further definition, the water and buffer used in the elution buffer can be considered to be amplification reagents. Regarding claims 10 and 11, p. 2 paragraph 20 describes the silica surface as glass fibers or silica-coated magnetic beads.
In one embodiment the elution described by Callahan is carried out in a solution of NaOH and 50 mM TRIS at pH 8.0, (p. 5 paragraph 85) which meets the limitations of present claim 1 and dependent claims 2-4. Because the recovered nucleic acids can then be used for PCR, they are reasonably considered to be free of substances that interfere with PCR. Regarding claim 5, the term “nucleic acid amplification reagent” is not defined in the claims or specification, it is seen as including any reagent that could be present in an amplification reaction, including for example the base and buffer present in the extraction solution.
The disclosure of Callahan et al. differs from that of the present claims in that it does not disclose an acidic wash buffer. However, Michelsen et al. discloses a method for isolating and purifying nucleic acids from a sample comprising diluting the sample with an acidic binding buffer, contacting the sample with a carrier material which is an inorganic hydroxide, separation, and elution in an alkaline solution. (column 2 lines 14-30) Furthermore in a preferred embodiment a wash buffer having a pH of between 3-6 and an elution buffer having a pH of 7.5-9 are used. (column 2 lines 31-36) In particular, the carrier material can be silica. (column 2 line 64 – column 3 line 4) The carrier can also be in the form of fibers or particles, as described in present claim 10. (column 3 lines 5-10) The binding buffer preferably contains a cation such as potassium, as well as a buffering ion which can be citrate. (col. 3 lines 11-28) Still further the wash buffer can use the same buffers (e.g. citrate) as the binding buffer. (column 3 lines 36-40)
It would have been obvious to one of ordinary skill in the art at the time of the invention to use an acidic wash solution such as the citrate buffer described by Michelsen et al. in a nucleic acid isolation method as described by Callahan et al. One of ordinary skill in the art would have seen the disclosure of Callahan as being fairly generic as to what wash steps can be used, and would have reasonably expected that the acidic wash steps described by Michelsen et al. would have worked in the protocol of Callahan et al. as well.
For these reasons the invention taken as a whole is prima facie obvious.
Conclusion
No claims are allowed in this action. 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 ANDREA OLSON whose telephone number is (571)272-9051. The examiner can normally be reached M-F 6am-3:00pm.
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/ANDREA OLSON/ Primary Examiner, Art Unit 1693 5/22/2026
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