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 .
Status of the Claims
Claims 1-9, 12-24 are pending in the application.
Claims 14-20 are withdrawn.
Claims 1-9, 12-13 and 21-24 are the subject of this office action.
Claim Rejections - 35 USC § 112(b)
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 23 and 24 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.
The term “pre-integrated” in claim 23 is a relative term which renders the claim indefinite. The term “pre-integrated” 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 prefix “pre” within the term indicates some form of chronological order, however no frame of reference is established to define the term. That is, pre-integrated implies that integration occurs prior to some specific point, but that point is not established or defined. Clarification is required.
Claim 24 is vague regarding “the pore openings”. There is no prior introduction of “pore openings” in the claims, therefore there is insufficient antecedent basis for this limitation in the claim. For the purposes of the present office action, this claim interpreted to refer to the pore size of the porous solid support recited in claim 1.
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 1-9, 12-13, and 21-23 are rejected under 35 U.S.C. 103 as being unpatentable over Nazareth et al. (US 2012/0083047 A1; previously cited) in view of Huttunen et al. (“Residual nanoparticle label immunosensor for wash-free C-reactive protein detection in blood” Biosensors and Bioelectronics 83 (2016) 54–59; previously cited) and Guckenberger et al (US 2020/0209235 A1; previously cited), as evidenced by Song et al (US 2010/0062543 A1; IDS entered) and Lelubre et al (Lelubre C, Anselin S, Zouaoui Boudjeltia K, Biston P, Piagnerelli M. Interpretation of C-reactive protein concentrations in critically ill patients. Biomed Res Int. 2013;2013:124021; previously cited).
Regarding claims 1-9, 12-13, and 21-23 Nazareth teaches devices for detecting the presence of an analyte in a biological sample (e.g. [0005]) on a test strip, comprising:
a “release medium” formed of a first material, wherein the release medium is configured to receive the biological sample (e.g. [0005]), for example “In operation, a liquid sample is applied to sample receiving material 12, which is in contact with a proximal end of biphasic chromatographic substrate 18” ([0045], Fig. 3); also “Referring to FIG. 5, a biphasic chromatographic substrate 18 is shown including a release medium 30” (Fig. 5, [0056]) (i.e. a flow path configured to receive a fluid sample; a sample receiving zone coupled to the flow path, as in claim 1); and that the fluid samples include blood samples ([0024] (as in claim 12);
a capture medium located downstream from the release medium and in fluid communication with the release medium, the capture medium defining a result site (i.e. a capture zone) ([0005]), for example a result site 36 ([0056], Fig. 5, site 36), a result site 36 having capturable binding member, e.g., antibody is located at result site 36 ([0046], Fig. 3, site 36); where the antibody is specific to the antigen (i.e. analyte) ([0025] “antibody”, or fragments thereof, which recognizes and binds an antigen, [0026] capture antibody) (i.e. a capture zone coupled to the flow path downstream of the sample receiving zone and comprising an immobilized capture agent specific to an analyte of interest, as in claim 1); (i.e. the immobilized capture agent comprises an antibody or a fragment thereof specific to the analyte of interest, as in claim 8);
a labeled binding member reactive with a first epitope of the analyte to be detected in the biological sample, the labeled binding member being releasably disposed on the release medium (e.g. [0005]), where the release medium is upstream of the capture region, for example “Referring to FIG. 3A, a band 26 formed from a labeled conjugate (labeled binding member), e.g., an antibody-metal sol is deposited on release medium 30 downstream from sample receiving material 12. Band 26 includes a labeled binding member reactive with a particular site (sometimes referred to as a “first epitope”) on the analyte of interest. The labeled binding member further comprises a detectable label” ([0041], Figs. 3 and 5, labeled binding member band 26 upstream from capture zone 36, [0056]) (i.e. a labeled antibody or fragment thereof coupled to the flow path upstream of the capture zone specific to the analyte of interest, as in claim 1) (i.e. the labeled antibody is configured to flow with bound analyte of interest in the flow path to the capture zone when the fluid sample is received on the assay test strip, as in claim 3); and “The presence of the analyte” “is determined by observing the presence of the detectable label at threshold site 34 and result site 36” (i.e. “wherein the labeled antibody bound to the analyte of interest is configured to be captured at the capture zone and emits a detectable signal on a dose response curve having a single rising phase, as in claim 4).
It is noted that claims 4 and 21 “a dose response curve having a single rising phase” (claim 4) and “oversized particles configured to bind the analyte of interest are present in an amount sufficient to retain a first quantity of analyte of interest upstream of the capture zone such that a second quantity of analyte of interest that is not retained by the antibody-conjugated oversized particles and binds to the labeled antibody or fragment thereof generates a signal at the capture zone resulting in a single rising phase dose response curve as the second quantity of the analyte of interest increases” (claim21). Thus, both claims recite a function of the test strip in producing a dose response curve having a single rising phase, wherein it appears that this functional feature is a result of binding some amount of analyte of interest to the antibody-conjugated oversized particles. Further, claim 1 provides that the oversized particles are present on the assay test strip in an amount to bind 5 to 150 ug/mL of analyte interest, therefore, it is assumed that the oversized particles must be present in an amount to bind somewhere within this recited range of analyte of interest in order to fulfill the functional limitation of creating a dose response curve having a single rising phase as recited in claims 4 and 21, wherein modification and optimization of the prior art to meet this limitation is discussed at length below. A test strip which teaches all structural features of these claims is understood to be capable of performing this recited function, since the structural features are understood to enable the functional features in a claim to a device, regardless of whether the prior art explicitly teaches the same functional limitation.
Additionally, whether or not a dose response curve has a single rising phase is understood to be a result of the specific concentrations assayed, and not an inherent structural feature of the claimed assay test strip. For example, even in the case of an analyte measured on an assay test strip which provides no specific structural features for overcoming the hook effect, most analytes would provide signal on a dose response curve having a single rising phase over at least some range of analyte concentration. That is, since in a lateral flow assay such as the one taught by Nazareth in view of Huttunen and Guckenberger (wherein a threshold amount of analyte is captured by a scavenger/oversized particle component while any additional analyte is bound to a labeled detection reagent and flows downstream to a capture zone comprising a capture reagent specific for the analyte) one of ordinary skill would generally expect the signal from the capture zone to increase with increasing analyte concentration in the sample (at least for any concentration of analyte above the threshold, because increasing analyte concentration corresponds to increased labeled detection reagent-analyte complex bound in the capture zone), thereby producing a dose response curve having a single rising phase (over at least some range of analyte concentration). For at least these reasons, the assay test strip of Nazareth in view of Huttunen and Guckenberger is understood to read on this limitation of the claim.
Nazareth also teaches the devices comprise:
a “scavenger binding member” located on one of the release medium and the capture medium upstream from the result site (i.e. in the flow path upstream of the capture zone), the scavenger binding member configured to directly or indirectly bind with a predetermined threshold concentration of the analyte (i.e. conjugated to an antibody specific to the analyte of interest to form antibody-conjugated binding member conjugate) (e.g. [0005]);
where the scavenger binding member is immobilized at a threshold site located upstream of the result site on the capture medium (e.g. [0005]), the scavenger binding member may be immobilized at a threshold site located upstream of the result site (i.e. upstream of the capture site) on the capture medium ([0006]), and where the scavenger binding member is at least one of immobilized on the capture medium and releasably placed on the release medium ([0010]) (e.g. [0043], FIGS. 3A-3B, a threshold site 34 having a scavenger binding member).
For example, Nazareth teaches that “The scavenger binding member is immobilized at threshold site 34” “and does not advance with the fluid front. Once the threshold concentration of analyte has been met, any excess analyte moves with the fluid front toward result site 36, where it is immobilized by the capture binding member” ([0043]-[0045]). These teachings of a “scavenger binding member” read on a binding component which is specific to the analyte. The recited “oversized particle” is also a binding component which is specific to the analyte. The teachings of the binding component also read on the recitations of where this binding component “is in the flow path upstream of the capture zone”, the binding component “conjugated to an antibody specific to the analyte of interest to form” antibody-conjugated binding component conjugates of a configuration “to remain upstream of the capture zone when the fluid sample is received on the assay test strip.”
It is noted that although, as described above, the reference teaches claims 3 and 4 as recited, with respect to the recitations “the labeled antibody or fragment thereof is configured to flow with bound analyte of interest in the flow path to the capture zone when the fluid sample is received on the assay test strip” (claim 3); “wherein the labeled antibody bound to the analyte of interest is configured to be captured at the capture zone and emits a detectable signal” (claim 4); it is noted that a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. In the instant case, Nazareth teaches the claim limitations as discussed supra, yet nonetheless, even if the teachings would not disclose the intended use, since the prior art structure is capable of performing the intended use, then it meets the claim.
Regarding claim 2, Nazareth further teaches as noted above:
a “release medium” formed of a first material, wherein the release medium is configured to receive the biological sample (e.g. [0005], Figs. 3-5) (i.e. the flow path is configured to receive a fluid sample comprising the analyte of interest); and
that “The scavenger binding member is immobilized at threshold site 34” “and does not advance with the fluid front. Once the threshold concentration of analyte has been met, any excess analyte moves with the fluid front toward result site 36, where it is immobilized by the capture binding member” ([0043]-[0045]). These teachings of a “scavenger binding member” read on a binding component which is specific to the analyte.
Since Nazareth also teaches that the scavenger binding member is configured to directly or indirectly bind with a predetermined threshold concentration of the analyte (e.g. [0005]); and that for example teaches a result site ([0056], Fig. 5, site 36); “a result site 36 having capturable binding member, e.g., antibody is located at result site” ([0046], Fig. 3, site 36); where the antibody is specific to the antigen (i.e. analyte) ([0025] “antibody”, which recognizes and binds an antigen, [0026] capture antibody), these teachings that both the scavenger binding member and the capture (result site) binding member are both specific to the labeled analyte, read on the recitation of “wherein the labeled antibody and the antibody-conjugated” binding member “compete to specifically bind the analyte of interest,” since both the scavenger binding member and the capture (result site) binding member are both specific to the labeled analyte and would therefore compete for available labeled analyte binding sites (as in claim 2).
Although Nazareth teaches a scavenger binding member which is specific to the analyte and remains upstream of the capture zone, and a porous solid support, Nazareth doesn’t explicitly teach that the scavenger binding member may comprise an oversized particle of a size and dimension to remain upstream of the capture zone wherein the porous solid support has a pore size smaller than the oversized particles (claim 1); wherein the oversized particles are present on the assay test strip in an amount to bind to 5 to 150 ug/ml of analyte of interest (claim 1); that the oversized microparticle competes to bind the analyte (claim 2); that the microparticle is of about 10 μm to about 15 μm in diameter (claim 1); or that the analyte comprises C-reactive protein (claim 13); wherein the oversized particles are about 250 times the size of the labeled antibody (claim 22).
However, Huttunen teaches that “Current diagnostic immunotechnologies are universally based on the measurement of the bound label-antibody fraction in direct binding or sandwich-assay type approaches” and that “The advantage of detecting the nonbound fraction of the labelled antibody instead of the bound fraction is the high dynamics and the suggested increased flexibility in the selection of the detection mode” and applies this concept to “quantitative proof-of-concept set-up” “through blood-based detection of C-reactive protein (CRP)” (e.g. Pg. Abstract) (i.e. fluid sample is blood, also as in claim 12). Huttunen et al. teaches that in the art of lateral flow assays, known methods and devices comprise micro and nano particle assays (e.g. Pg. 55, left column, 2nd ¶). In particular, Huttunen teaches the use of oversized particles which are functionalized by coupling of the anti-human CRP antibody to the microparticles (MPs) (Pg. 55, section 2.1.1 – Materials polystyrene oversized microparticles, section 2.1.4 – oversized microparticles functionalized with anti-human CRP). That is, the analyte of interest comprises C-reactive protein (CRP) and the antibody or fragment thereof conjugated to the oversized particle comprises an anti-CRP antibody or fragment thereof bound to the CRP, as in claim 13), where the large microparticle used is a microparticle (MP) of 3048 nm in diameter (Pg. 55, section 2.1.1 1st sentence).
Huttunen also teaches that the oversized particles bind an amount of the analyte in the sample where the analyte is labeled with fluorescent Eu-NPs, while a remaining amount of labeled analyte remains free in solution (i.e. not bound to the oversized particles). The labeled analyte bound to oversize particles is separated from the free labeled analyte by size exclusion filtration, through which the oversized particles with bound labeled analyte remain upstream of the filter membrane, while the free labeled analyte is allowed to pass through the filter membrane and is subsequently detected (e.g. Pg. 56, section 3.1, Fig. 1 – light blue Microparticle (i.e. oversized particle) functionalized with Ab specific for the CRP analyte captures labeled analyte (grey oval labeled with fluorescent Eu-NP in pink) ). These teachings read on the recitations of an oversized particle of a size and dimension to remain upstream of a detection zone.
Regarding the recitations of a size and dimension “to remain upstream of the capture zone” (claim 1); it is noted that a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. In the instant case, although Nazareth et al. and Huttunen et al. do not specifically employ the terminology of the intended use recitations, if the references teach a device which meets the structural limitations of the instant claims, the device taught would necessarily be capable of being used in the manner recited in the instant claims. In particular, as defined in the instant specification “the oversized particle is about 1 μm to about 15 μm in diameter” (e.g. Specification at [0007]), which as instantly recited would be of “a size and dimension” so as to perform the intended use. As defined by the specification a particle within the same size range specified would necessarily be capable of performing the intended use, as taught by the Huttunen et al. reference, the oversized microparticle (MP) is of 3048 nm in diameter (Pg. 55, section 2.1.1 1st sentence) which meets the same structural dimensions of the particle defined in the specification. If the prior art structure is capable of performing the intended use, then it meets the claim.
Huttunen further teaches that the taught separation immunoassay is applicable for immunorecognition-based diagnostics, and provides the advantages that “assessment of the analyte concentration is performed from the residual, soluble fraction after simple and wash-free physical separation” of the microparticle bound labeled analyte and free labeled analyte, and that “The residual detection principle is evidently applicable for particle-based methods and versatile for biorecognition reactions of high binding-affinity. With the model analyte, CRP, a sensor performance with satisfactory sensitivity and wide analytical range was achieved. The opportunity for a wash-free procedure enables fast and discreet analysis of whole blood samples and constitutes an option for the development of miniaturized POC systems (e.g. Pg. 58, section 4).
Therefore, It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the lateral flow assays of Nazareth where a portion of the labeled analyte is retained at a site where a “scavenger” binding component is specific to the labeled analyte and remains upstream of the capture detection zone, by substituting the “scavenger” binding component with an oversized particle conjugated to an antibody specific to the analyte of interest to form antibody-conjugated oversized particles of a size dimension to remain upstream of a subsequent detection site, as taught by Huttunen, in order to have oversized particles in the flow path upstream of the capture zone, the oversized particles conjugated to an antibody specific to the analyte of interest to form antibody-conjugated oversized particles of a size and dimension to remain upstream of the capture zone when the fluid sample is received on the assay test strip, as in claim 1, or to have the labeled antibody and the antibody-conjugated oversized particles compete, as in claim 2. One would have been motivated to substitute the components as described above, because Nazareth teaches that in lateral flow assays where it is desirable to sequester a calibrated amount of labeled analyte, this sequestration may be achieved by having a designated region on the lateral flow device where an amount of the labeled analyte may be sequestered and bound by a “scavenger” binding component site (e.g. [0011], and as discussed supra), and because Huttunen teaches that separation of an amount of labeled analyte from a sample can be advantageously achieved using an oversized particle functionalized with an anti-analyte antibody, which also sequesters an amount of labeled analyte from the sample and allows for separation by the size of the oversized particle, which has the advantages of: “The advantage of detecting the nonbound fraction of the labelled antibody instead of the bound fraction is the high dynamics and the suggested increased flexibility in the selection of the detection mode” (e.g. Abstract) and that “a sensor performance with satisfactory sensitivity and wide analytical range was achieved. The opportunity for a wash-free procedure enables fast and discreet analysis of whole blood samples and constitutes an option for the development of miniaturized POC systems” (e.g. Pg. 58, section 4). Additionally, one would recognize that adjustment of the particle size such that it is prevented from flowing downstream in the lateral flow membrane via size exclusion is an alternative and substitutable method of immobilizing analyte bound to a scavenger component as taught by Nazareth, wherein such a method of immobilization is particularly suitable in the device of Nazareth because Nazareth teaches that it is preferable to achieve immobilization of reagents on the membrane by a non-chemical means (Par. 44).
One would have had a reasonable expectation of success in making this modification because both Nazareth and Huttunen teach that it is well known in the art to incorporate particles in lateral flow assays (e.g. Huttunen, Pg. 55, left column 1st 2nd ¶s), and because the functionalized oversized microparticles taught by Huttunen are of a size and dimension that would work on a lateral flow device in the manner intended, and since Nazareth also teaches use of particles in the lateral flow device (e.g. [0026] [0027]). Also, since both components (the scavenger binding member and the oversized particle) are components known in the art to function as binding members in immunoassays, one would have a reasonable expectation of success in substituting the components.
Furthermore, It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the lateral flow assays as taught by Nazareth, by substituting the “scavenger” binding component with an oversized particle conjugated to an antibody specific to the analyte of interest to form antibody-conjugated oversized particles of a size of about 10 μm to about 15 μm in diameter (as in claim 1). Although Huttunen discloses microparticles that are about 3um in diameter, which does not fall within the claimed range, one of ordinary skill in the art could be expected to arrive at the claimed range of 10um-15um as a result of routine optimization.
The prior art differs from the claimed invention with respect to the size of the oversized particle. The court has stated that, generally, such differences amount to mere optimization and will not support patentability unless there is evidence indicating the claimed feature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) (Claimed process which was performed at a temperature between 40°C and 80°C and an acid concentration between 25% and 70% was held to be prima facie obvious over a reference process which differed from the claims only in that the reference process was performed at a temperature of 100°C and an acid concentration of 10%.); see also Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382 ("The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages."); In re Hoeschele, 406 F.2d 1403, 160 USPQ 809 (CCPA 1969) (Claimed elastomeric polyurethanes which fell within the broad scope of the references were held to be unpatentable thereover because, among other reasons, there was no evidence of the criticality of the claimed ranges of molecular weight or molar proportions.). For more recent cases applying this principle, see Merck & Co. Inc. v. Biocraft Lab. Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. denied, 493 U.S. 975 (1989); In re Kulling, 897 F.2d 1147, 14 USPQ2d 1056 (Fed. Cir. 1990); and In re Geisler, 116 F.3d 1465, 43 USPQ2d 1362 (Fed. Cir. 1997). in KSR International Co. v. Teleflex Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007), the Supreme Court held that "obvious to try" was a valid rationale for an obviousness finding, for example, when there is a "design need" or "market demand" and there are a "finite number" of solutions. 550 U.S. at 421.
MPEP 2144 sets forth Applicant’s burden for rebuttal of a prima facie case of obviousness based upon routine optimization. Applicant must provide either a showing that the particular amount or range recited within the claims is critical; and/or a showing that the prior art reference teaches away from the claimed amount. In the instant case, the specification as filed provides no evidence that the particular amount or range recited within the claims is critical because the specification indicates that a wider range of sizes from 1µm-15µm can be used with the disclosed invention (Par. 58), and provides no indication or evidence that the claimed range of 10µm-15µm is critical.
As it applies to the instant case, one of ordinary skill in the art would be motivated to arrive at an oversized particle of about 10µm to about 15µm in diameter as a result of routine optimization of Nazareth in view of Huttunen because one would be motivated to use the proper particle size to achieve the desired size exclusion of oversized particles taught by Huttunen (wherein such size exclusion requires that the diameter of the particle be greater than the diameter of the pore, such that the particle is incapable of passing through the pore). For example, Nazareth teaches that the capture medium on which the scavenger binding component is immobilized may have a range of pore sizes (Par. 36: capture medium 32 may be formed from a material that permits immobilization of reagents. Non-limiting examples of materials useful as capture medium 32 comprise a microporous polymeric film of nitrocellulose, nylon (e.g., nylon 66), or similar materials or combinations of such materials; Par.37: Materials for use as capture medium 32 preferably have a pore size in the range of about 5um to about 20um). Therefore, one of ordinary skill in the art would be motivated to optimize the oversized particles which can be separated from the unbound labeled analyte by size exclusion, as is taught by Huttunen et al. (e.g. Pg. 56, section 3.1) to a larger diameter in the range of 10um to 15um in order to enable the size exclusion of the oversized particles in a lateral flow device such as the one taught by Nazareth with a preferred capture medium pore size of about 5um.
One would have been motivated to combine the teachings as above, because Huttunen teaches that separation of an amount of labeled analyte from a sample can be advantageously achieved by using an oversized particle functionalized with an anti-analyte antibody, which also sequesters an amount of labeled analyte from the sample and allows for separation by the size of the oversized particle, which carries the advantages of: “The advantage of detecting the nonbound fraction of the labelled antibody instead of the bound fraction is the high dynamics and the suggested increased flexibility in the selection of the detection mode” (e.g. Pg. Abstract) and that “a sensor performance with satisfactory sensitivity and wide analytical range was achieved. The opportunity for a wash-free procedure enables fast and discreet analysis of whole blood samples and constitutes an option for the development of miniaturized POC systems” (e.g. Pg. 58, section 4). Additionally, one would recognize that adjustment of the particle size such that it is larger than the pore size of the porous support and is thereby prevented from flowing downstream in the lateral flow membrane via size exclusion is an alternative and substitutable method of immobilizing analyte bound to the scavenger component as taught by Nazareth, wherein such a method of immobilization is particularly suitable in the device of Nazareth because Nazareth teaches that it is preferable to achieve immobilization of reagents on the membrane by a non-chemical means (Par. 44).
One would have had a reasonable expectation of success in having the particle be of about 10 μm to about 15 μm in diameter since, because Nazareth and Huttunen teach that it is well known in the art to incorporate particles in lateral flow assays (e.g. Huttunen et al. Pg. 55, left column 1st 2nd ¶s); microparticles within the claimed range of about 10um to about 15um in diameter are known in the art to be suitable for use in lateral flow assays, as evidenced by Song, which teaches a lateral flow device 20 (Figs. 1-3) comprising microparticles (Par. 8: the detectable probe may be a latex microparticle; Par. 39: in some embodiments the diameter of the particulate probe ranges from about .01 microns to about 100 microns); and since Nazareth also teaches use of particles in the lateral flow device (e.g. [0026], [0027]), and teaches that the capture medium is preferably selected to bind capture reagents without the need for chemical coupling (i.e. a preferable embodiment could be one where size exclusion (non-chemical) is used to immobilize the threshold concentration of analyte) (Par. 44).
In addition, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the lateral flow assays as taught by Nazareth, by having the analyte comprise C-reactive protein, as taught by Huttunen, in order to have a device that detects C reactive protein because Huttunen teaches that “The magnitude and importance of CRP detection is rising especially in POC” (point of care) and because CRP is correlated to numerous diseases (e.g. Pg. 55, left column, 1st ¶). One would have been motivated to provide an assay for CRP in order to diagnose patients levels and to monitor disease state and progression.
Additionally, although Nazareth teaches the scavenger capturing analytes at a threshold concentration different than the instantly claimed range of 5 to 150 ug/ml (Par. 59), it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the lateral flow device such that the threshold concentration captured by the “scavenger” (modified herein to read on the instantly claimed oversized particle) is present on the assay test strip in an amount to bind 5 to 150ug/ml of analyte of interest.
One would be motivated to change the threshold concentration of analyte captured by the oversized particles in the invention of Nazareth in view of Huttunen in accordance with the chosen analyte of interest, because different analytes of interest are present in different samples at different concentration ranges. For example, as described above, one would be motivated to modify Nazareth for the detection of CRP. It is known in the prior art that normal concentrations of CRP greater than 10 mg/dL (equivalent to 100 ug/ml) are associated with a strong indication of infection as compared to lower concentrations of CRP (see Lelubre, Pg. 5, Col. 1, Par. 2). Thus, in the invention of Nazareth in view of Huttnen which has been modified for the detection of an analyte such as CRP, one would be motivated to provide oversized particles in an amount suitable to capture a threshold concentration in the range of 5 to 150 ug/ml for the purpose of overcoming the hook effect and for providing a test for markedly elevated levels of CRP. For example, one could provide oversized particles capable of capturing 100 ug/ml of CRP, such that the test strip indicates a positive result only when CRP exceeds this concentration and is thereby determined to be markedly elevated and indicative of infection. Beyond the specific example of CRP, one of ordinary skill would be generally motivated to provide oversized particles to capture a threshold concentration of target analyte that is relevant and suitable to the chosen target analyte.
One would have had a reasonable expectation of success in modifying the device for the detection of CRP because Nazareth teaches that the taught lateral flow immune-assay device is apt to analyze analytes comprising: antigens, antibodies, hormones, drugs, proteins associated with a cell (“cell proteins”), secreted proteins, enzymes, cell surface or transmembrane proteins, glycoproteins and other proteins, peptides, and carbohydrates ([0028]). In other words because Nazareth teaches that the device is capable of assaying analytes including cell proteins, one would have a reasonable expectation of success in assaying for C-reactive protein, which as taught by Huttunen is also applicable to immunorecognition based diagnostics (e.g. Huttunen, Pg. 58, right column, section 4 1st 2nd ¶s), and because Huttunen teaches that the method is “a simplified separation method suitable for measurements using practically any detection technology applying nanoparticles as labels” (Pg. 55, Col. 1, Par. 2), and “assessment of the analyte concentration is performed from the residual, soluble fraction after simple and wash-free physical separation of the bound and free reporter nanoparticles. The residual detection principle is evidently applicable for particle-based methods and versatile for biorecognition reactions of high binding-affinity. With the model analyte, CRP, a sensor performance with satisfactory sensitivity and wide analytical range was achieved. The opportunity for a wash-free procedure enables fast and discreet analysis of whole blood samples and constitutes an option for the development of miniaturized POC systems” (e.g. Pg. 58, section 4).
Regarding claim 1, Nazareth and Huttunen differ from the instant claim in that neither reference teaches that the oversized particle is a magnetic particle.
Regarding claim 1, Guckenberger teaches an assay test strip comprising:
A flow path for receiving a fluid sample; a sample receiving zone coupled to the flow path; a capture zone coupled to the flow path downstream of the sample receiving zone and comprising an immobilized capture agent specific to an analyte of interest (Abstract; Fig. 1A-1B);
and magnetic particles in the flow path upstream of the capture zone which are conjugated to an antibody or fragment thereof specific to the analyte of interest (Fig. 1B; Par. 9, 13: the lateral flow assay device may comprise a concentrating component such as a magnet, which may be coupled with a plurality of magnetic particles comprising a reagent that specifically binds to an analyte, such that the magnet may be used to immobilize the magnetic particles in a specific region of the device to ensure their proper reaction with the analyte of interest).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have further modified the assay test strip of Nazareth in view of Huttunen such that the antibody-conjugated oversized particles comprise magnetic particles, as taught by Guckenberger. Though Guckenberger teaches a different application of the magnetic particles (i.e. magnetic particles are allowed to flow into the capture zone in Guckenberger rather than remaining upstream of the capture zone as in the modified device of Nazareth in view of Huttunen), Guckenberger teaches that magnetic particles can be modified with a reagent such as an antibody which binds to analyte of interest, and teaches that the magnetic property of the particles is advantageous in allowing for specific manipulation and immobilization of the particles via the application of a magnetic field. Thus, one of ordinary skill in the art would be motivated to make the oversized particles magnetic in the lateral flow assay of Nazareth in view of Huttunen and Guckenberger because magnetic particles could be immobilized to remain upstream of the capture zone via the application of a magnetic field (i.e. both size exclusion and magnetism of the particles could be used synergistically to prevent the oversized particles from traveling downstream into the capture zone). One of ordinary skill in the art would have a reasonable expectation of success in making this modification because Nazareth and Guckenberger are both directed to lateral flow assay devices comprising particles modified with a reagent that specifically binds to the analyte of interest.
Regarding claims 5, 9, and 23, Nazareth teaches, as discussed supra, that for example “In operation, a liquid sample is applied to sample receiving material 12, which is in contact with a proximal end of biphasic chromatographic substrate 18” ([0045], Fig. 3); also “Referring to FIG. 5, a biphasic chromatographic substrate 18 is shown including a release medium 30” (Fig. 5, [0056]) (i.e. a flow path configured to receive a fluid sample; a sample receiving zone coupled to the flow path, as in claim 5). These teachings read on the recitation of “the flow path is configured to receive a fluid sample that does or does not comprise analyte of interest.” It is noted that with respect to the recitation “configured to receive a fluid sample that does or does not comprise analyte of interest”; a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. In the instant case, although Nazareth does not specifically employ the terminology of the intended use recitations, since the reference teaches a device which meets the structural limitations of the instant claims, in particular a sample receiving zone, the sample receiving region is capable of receiving a sample that does or does not contain analyte, therefore the device taught would necessarily be capable of being used in the manner recited in the instant claims. If the prior art structure is capable of performing the intended use, then it meets the claim.
Nazareth further teaches that “upon diffusion into capture medium 32, the diffusible sandwich becomes concentrated by the interaction of the binding member (the capturable affinity) with the scavenger binding member (the capture affinity) at threshold site 34 so as to capture the capturable sandwich complex as it moves across threshold site 34. Threshold site 34 is calibrated to capture either directly or indirectly a threshold concentration of analyte of interest” (i.e. the antibody-conjugated binding member specifically binds to a known quantity of analyte of interest, thereby retaining a known quantity of analyte of interest upstream of the capture zone, as in claim 5) “such that any analyte of interest in excess of the threshold concentration is available for binding at result site 36” ([0043]-[0045]).
Nazareth further teaches that “The scavenger binding member is immobilized at threshold site 34, preferably by simple adsorption and does not advance with the fluid front.” ([0044]), and that “the scavenger binding member is at least one of immobilized on the capture medium and releasably placed on the release medium” ([0010]) (i.e. the antibody-conjugated binding (scavenger) member is integrated onto a surface of the test strip, as in claim 9; wherein the surface into which the scavenger member is integrated is understood to read on a conjugate pad (as in claim 23) because it also comprises an integrated conjugate (Par. 5: scavenger binding member may be located on either the release medium or the downstream capture medium; Par. 34: release medium may also comprise the labeled conjugate))
Although Nazareth teaches a scavenger binding member which is an antibody-conjugated (scavenger) binding member that specifically binds to a known quantity of analyte of interest, thereby retaining a known quantity of analyte of interest upstream of the capture zone (as in claim 5), and that the antibody-conjugated binding (scavenger) member is integrated onto a surface of the test strip (as in claim 9, 23), Nazareth doesn’t explicitly teach that the scavenger binding member may comprise an oversized particle.
However, Huttunen teaches that “The advantage of detecting the nonbound fraction of the labelled antibody instead of the bound fraction is the high dynamics and the suggested increased flexibility in the selection of the detection mode” (e.g. Pg. Abstract). In particular, Huttunen teaches the use of oversized particles which are functionalized by coupling of the anti-human CRP antibody to the microparticles (MPs) (Pg. 55, section 2.1.1 – Materials polystyrene oversized microparticles, section 2.1.4 – oversized microparticles functionalized with anti-human CRP) (i.e. antibody-conjugated oversized particles specifically bind to a known quantity of analyte of interest). Huttunen also teaches that the oversized particles bind an amount of the analyte in the sample where the analyte is labeled with fluorescent Eu- NPs, and an unbound remaining amount of labeled analyte which remains in solution, are both separated by filtration, through which the oversized particles with bound labeled analyte remain upstream of the filtered through labeled analyte, which is subsequently detected (e.g. Pg. 56, section 3.1, Fig. 1 – light blue Microparticle (i.e. oversized particle) functionalized with Ab specific for the CRP analyte captures labeled analyte (grey oval labeled with fluorescent Eu-NP in pink)).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the lateral flow assays where a “scavenger” binding component is specific to the labeled analyte and remains upstream of the capture detection zone, as taught by Nazareth, by substituting the “scavenger” binding component with an oversized particle conjugated to an antibody specific to the analyte of interest, as taught by Huttunen in order to have the antibody-conjugated oversized particles specifically bind to a known quantity of analyte of interest, thereby retaining a known quantity of analyte of interest upstream of the capture zone (as in claim 5) and to have the antibody-conjugated oversized particles integrated onto a surface of the test strip (as in claim 9). One would have been motivated to substitute the components as above, because Nazareth teaches that in lateral flow assays where it is desirable to sequester a calibrated amount of labeled analyte, this may be achieved by having a designated region on the lateral flow device where an amount of the labeled analyte may be sequestered and bound by a “scavenger” binding component site (e.g. [0011], and as discussed supra), and because Huttunen teaches that separation of an amount of labeled analyte from a sample can be advantageously achieved by using an oversized particle functionalized with an anti-analyte antibody, which also sequesters an amount of labeled analyte from the sample and allows for separation by the size of the oversized particle, which carries advantages of: “The advantage of detecting the nonbound fraction of the labelled antibody instead of the bound fraction is the high dynamics and the suggested increased flexibility in the selection of the detection mode” (e.g. Pg. Abstract) and that “The opportunity for a wash-free procedure enables fast and discreet analysis of whole blood samples and constitutes an option for the development of miniaturized POC systems” (e.g. Pg. 58, section 4).
One would have further been motivated to combine the components in order to have the antibody-conjugated oversized particle integrated onto a surface of the test strip such as a conjugate pad (as in claim 9, 23) because this would allow the particles to remain upstream of the detection zone, sequestering a known amount of labeled analyte at the site where the oversized particles are integrated onto the device, essentially performing a separation of a determined amount of labeled analyte which would remain sequestered on the oversized particles, from the remaining free labeled analyte amount which would flow to the detection capture zone, which as taught by both Nazareth and Huttunen is a desirable design option as it provides advantages of controlling the amount of labeled analyte that reaches the detection capture zone, and because Huttunen teaches that separation of an amount of labeled analyte from a sample can be advantageously achieved by using an oversized particle functionalized with an anti-analyte antibody, which also sequesters an amount of labeled analyte from the sample and allows for separation by the size of the oversized particle, with the advantages of “The advantage of detecting the nonbound fraction of the labelled antibody instead of the bound fraction is the high dynamics and the suggested increased flexibility in the selection of the detection mode” (e.g. Pg. Abstract).
One would have had a reasonable expectation of success in substituting the components because Huttunen teaches that it is well known in the art to incorporate particles in lateral flow assays (e.g. Huttunen et al. Pg. 55, left column 1st 2nd ¶s), and since Nazareth also teaches use of particles in the lateral flow device (e.g. [0026] [0027]). Also, since both components, the scavenger binding member and the oversized particle are components known in the art to work and perform the function of binding members incorporated in immunoassays, one would have a reasonable expectation of success in substituting the components.
Regarding claims 6 and 7, Nazareth teaches that a “Control site 38 has immobilized thereon a capture component (control capture binding member) that is reactive with the labeled control member. Accordingly, the labeled control member will travel along the fluid front of the biological sample and ultimately bind with the control capture binding member immobilized at control site 38. Preferably, control site 38 is located downstream of both threshold site 34 and result site 36.” (i.e. further comprising a control zone downstream of the capture zone, as in claim 6); “Detection (by color development) of the labeled control member at control site 38 informs a user that the biological sample has in fact traveled downstream and reconstituted the labeled binding components.” (i.e. the control zone comprises antibody that specifically binds to the labeled antibody or fragment thereof that does not bind to analyte of interest and flows past the capture zone, as in claim 6) (e.g. [0047], [0056], Figs. 4, 5 – control site 38). With respect to the recitations “when the fluid sample does not comprise an analyte of interest, the labeled antibody or fragment thereof flows to the control zone and emits an optical signal at the control zone only, indicating absence of the analyte of interest in the fluid sample” (claim 7), it is noted that the recitations are drawn to the intended use of the device, a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. In the instant case, although Nazareth does not specifically employ the terminology of the intended use recitations, since the reference teaches a device which meets the structural limitations of the instant claims, as noted above the device comprises a control zone as claimed, therefore the device taught would necessarily be capable of being used in the manner recited in the instant claim 7. If the prior art structure is capable of performing the intended use, then it meets the claim.
Notwithstanding the above, in the interest of compact prosecution, it is further noted that Nazareth further teaches for example that “FIG. 4B, a test result in which only control site 38 has exhibited an identifiable color development is shown. As such, these results quickly inform a user that the biological sample did not include a surge level of” analyte “and also that this particular device is functional. That is, the color development at the control site informs the user that the fluid sample passed through the length of the device and therefore reconstituted the labeled binding member.” ([0053]), which exemplifies that the taught device is capable of being used in the manner recited.
Regarding claim 22, Nazareth further teaches that the oversized particles are about 250 times the size of the labeled antibody. That is, as described in the rejection above, the oversized particles in modified Nazareth have a diameter of 10-15um, and Nazareth teaches a labeled antibody or fragment thereof, wherein the labeled antibody is labeled with a gold colloid having a mean particle size of about 50nm to about 100nm (Par. 41). Wherein it is noted that 10um divided by 250 is equal to 40nm and 15um divided by 250 is 60nm, such that the size range of the gold colloid conjugate (i.e. labeled antibody) taught by Nazareth overlaps with the size range required of a labeled antibody in order for an oversized particle of 10-15um in diameter to be about 250 times the size of the labeled antibody.
Claim 24 is rejected under 35 U.S.C. 103 as being unpatentable over Nazareth et al. (US 2012/0083047 A1; previously cited) in view of Huttunen et al. (“Residual nanoparticle label immunosensor for wash-free C-reactive protein detection in blood” Biosensors and Bioelectronics 83 (2016) 54–59; previously cited) and Guckenberger et al (US 2020/0209235 A1; previously cited), as evidenced by Song et al (US 2010/0062543 A1; IDS entered) and Lelubre et al (Lelubre C, Anselin S, Zouaoui Boudjeltia K, Biston P, Piagnerelli M. Interpretation of C-reactive protein concentrations in critically ill patients. Biomed Res Int. 2013;2013:124021; previously cited) as applied to claim 1 above, and further in view of Posthuma-Trumpie et al (Lateral flow (immuno)assay: its strengths, weaknesses, opportunities and threats. A literature survey. Anal Bioanal Chem. 2009 Jan;393(2):569-82. doi: 10.1007/s00216-008-2287-2. Epub 2008 Aug 13.) and Ahmad et al ( Investigating membrane morphology and quantity of immobilized protein for the development of lateral flow immunoassay. J Immunoassay Immunochem. 2012 Jan;33(1):48-58.).
Regarding claim 24, the prior art references teach the assay of claim 1, as discussed above. The references differ from claim 24 in that they do not explicitly teach the assay wherein the pore openings are between 0.1um and 3um.
However, Posthuma-Trumpie and Ahmad both teach that of membranes with pore openings between 0.1um and 3um are known in the art to be used for assay test strips (Posthuma-Trumpie, Pg. 572, Col. 1, last Par.; Ahmad, Pg. 52, Par. 2). The references further indicate that decreasing the pore size of a test strip membrane can be advantageous in a test strip assay. Both references teach that decreasing pore size of the membrane increases assay sensitivity (Ahmad, Pg. 49, Par. 2-3: pore structure of the membrane is the crucial factor affecting sensitivity of the immunoassay. Membranes with lower pore sizes have a greater surface area and are able to bind more detecting reagent onto the reagent capture zone, producing a more sensitive assay; Posthuma-Trumpie, Pg 572, Col. 1,-Pg, 573, Col. 1, Par. 4: decreasing pore size decreases flow rate through the membrane, increasing the amount of time that reagent have to interact with the analyte. Increasing pore size widens the test line and thereby decreases the sensitivity of the assay).
Therefore, it would have been obvious to one of ordinary skill in the art to modify the assay test strip to further decrease the pore size taught by Nazareth to a smaller pore size in the range of 0.1um and 3um as taught by Posthuma-Trumpie and Ahmad. One of ordinary skill in the art would be motivated to make this modification because both Posthuma-Trumpie and Ahmad teach that decreasing pore size of an assay membrane is advantageous in increasing assay sensitivity. One of ordinary skill in the art would have a reasonable expectation of success in making this modification because Nazareth, Posthuma-Trumpie, and Ahmad are all directed to immunoassays comprising porous membranes.
Response to Arguments
Applicant’s arguments filed 28 January 2026 have been fully considered.
Previous grounds of 103 rejection are withdrawn in view of the amendment of the claims, and new grounds of 103 rejection which address the amended claims are presented above. Arguments relevant to the rejection of the amended claims are addressed here.
Applicant argues that Nazareth teaches a scavenger antibody that is immobilized by adsorption on the membrane and does not teach an oversized particle. Applicant argues that pore size in Nazareth is chosen to support capillary flow and is not used to retain particulate beads upstream during sample flow. Applicant argues that Nazareth neither teaches not motivates optimization of particle size to be retained upstream during lateral flow.
Applicant argues that Huttunen does not teach or suggest a lateral flow strip or particles that remain upstream on a strip during sample flow. Applicant argues that one would not have been motivated to combine the disparate teaching of Huttunen with those of Nazareth.
Applicant argues that a rejection based on optimization of the size of the oversized particle is misplaced because the amended claims do not merely adjust a result-effective variable, but rather recite specific structural and dimensional relationships that fundamentally alter transport behavior on the lateral flow strip. Applicant argues that the cited references do not provide guidance or motivation to select and combine these features as claimed.
These arguments are not persuasive. Nazareth teaches that in the disclosed lateral flow assay where it is desirable to sequester a calibrated amount of labeled analyte, this may be achieved by having a designated region on the lateral flow device where an amount of labeled analyte may be sequestered and bound by a scavenger binding component, and Huttunen teaches that separation of an amount of labeled analyte from a sample can be advantageously achieved by using an oversized particle functionalized with an anti-analyte antibody, which also sequesters an amount of labeled analyte from the sample and allows for separation by the size of the oversized particle. Though Huttunen is not specific to a lateral flow assay format, Huttunen teaches that the disclosed assay format (i.e. a residual particle label sensor which facilitates separation of a microparticle bound fraction of analyte from an unbound fraction of analyte by physical separation and size exclusion) may be applied to other POC devices and assay formats (Pg. 58, Col. 2). Huttunen teaches that this assay mechanism is advantageous in increasing sensitivity and dynamic range of an immunoassay and in facilitating wash-free detection of an analyte. Further, since Nazareth teaches a preferred pore size of the porous membrane of the disclosed lateral flow device (5-20um), one of ordinary skill in the art would be motivated to optimize the oversized particle diameter to facilitate the desired size exclusion in the modified device of Nazareth in view of Huttunen, because one would recognize that the desired size exclusion could not be achieved by a 3um oversized particle disposed on a membrane with a 10um pore size. The specific structural and dimensional relationship between pore size and oversized particle diameter that is present in the instant claim is present and obvious in the modified invention of Nazareth in view of Huttunen, such that there is sufficient motivation to optimize the oversize particle size based on the disclosed membrane pore size.
Regarding Guckenberger, applicant argues that the magnetic particles in Guckenberger are not used to teach or inform a flow path configured to pass a labeled antibody while preventing flow of the oversized beads, as recited in the amended claims. This argument is not persuasive because Guckenberger is not relied upon to teach all of these features of the instant claim. Guckenberger is only relied upon to teach that magnetic particles may be advantageously immobilized by nature of their magnetic properties.
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.
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/ELLIS FOLLETT LUSI/Examiner, Art Unit 1677
/CHRISTOPHER L CHIN/Primary Examiner, Art Unit 1677