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
Acknowledgement is hereby made of receipt and entry of the communication filed on Jan. 14, 2026. Claims 1-19 and 22 are pending. Claim 22 is withdrawn. Claims 1-19 are currently examined.
Election/Restrictions
Applicant's election without traverse of Group I (Claims 1-19), directed to a method of detecting a virus, in the reply filed on Jan. 14, 2026, is acknowledged.
Accordingly, claim 22 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group.
Claim Rejections - 35 USC § 112(a) (Written Description)
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.
Claims 1-19 are rejected under 35 U.S.C. 112(a) 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, at the time the application was filed, had possession of the claimed invention.
To satisfy the written description requirement, a patent specification must describe the claimed invention in sufficient detail that one skilled in the art can reasonably conclude that the inventor had possession of the claimed invention. See, e.g., Moba, B.V. v. Diamond Automation, Inc., 325 F.3d 1306, 1319, 66 USPQ2d 1429, 1438 (Fed. Cir. 2003); Vas-Cath, Inc. v. Mahurkar, 935 F.2d at 1563, 19 USPQ2d at 1116. However, a showing of possession alone does not cure the lack of a written description. Enzo Biochem, Inc. v. Gen-Probe, Inc., 323 F.3d 956, 969-70, 63 USPQ2d 1609, 1617 (Fed. Cir. 2002). For example, it is now well accepted that a satisfactory description may be found in originally-filed claims or any other portion of the originally-filed specification. See In re Koller, 613 F.2d 819, 204 USPQ 702 (CCPA 1980); In re Gardner, 475 F.2d 1389, 177 USPQ 396 (CCPA 1973); In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). However, that does not mean that all originally-filed claims have adequate written support. The specification must still be examined to assess whether an originally-filed claim has adequate support in the written disclosure and/or the drawings. See MPEP 2163. I.
In Regents of the University of California v. Eli Lilly and Co. 119 F.3d 1559, 43 USPQ2d 1398 (Fed. Cir. 1997), the Court decided that adequate written description of genetic material "requires a precise definition, such as by structure, formula, chemical name, or physical properties, not a mere wish or plan for obtaining the claimed chemical invention." Id. 43 USPQ2d at 1404 (quoting Fiefs, 984 F.2d at 1171, 25 USPQ2d at 1606). In AbbVie Deutschland GMBH & Co. v. Janssen Biotech, Inc. (Court of Appeals, Federal Circuit 2014), the Court ruled that “[W]ith the written description of a genus, however, merely drawing a fence around a perceived genus is not a description of the genus. One needs to show that one has truly invented the genus, i.e., that one has conceived and described sufficient representative species encompassing the breadth of the genus. Otherwise, one has only a research plan, leaving it to others to explore the unknown contours of the claimed genus. See Ariad, 598 F.3d at 1353 (The written description requirement guards against claims that “merely recite a description of the problem to be solved while claiming all solutions to it and . . . cover any compound later actually invented and determined to fall within the claim' s functional boundaries.”).”
The instant claims are drawn to a method for detecting a virus, comprising: contacting an air sample with a binding agent on a support, thereby binding at least a portion of virus particles in the air sample to the binding agent on the support; contacting the virus particles bound to the binding agent on the support with a reporter that binds specifically to and/or is cleaved specifically by a protein of the virus particles; and detecting the presence of the reporter bound to and/or cleaved by the surface protein of the virus particles or the glycoprotein of the virus particles. The claims are general in almost all elements of the claimed invention.
The Specification of the instant application shows illustrations and descriptions on general knowledge and practices based on basic biology, assay chemistry, and processes in the art of virus detection, such as those for SARS-CoV-2 and influenza virus. See e.g., Figs. 2-12 and Examples 2-3. However, these teachings do not show that the invention as claimed has been possessed by the Applicant, especially considering that the claims encompass a method of detecting virus particles in an air sample by directly contacting an air sample to a binding agent on a support.
The Specification teaches that FLIR manufactures a bioaerosol trigger, the IBAC (Instantaneous Biological Aerosol Collector, FIG. 13) that detects biothreat particles in an airstream using a proprietary algorithm that analyzes particle size, count, and bio-fluorescence to classify biological threats, and that once the trigger alarms, the IBAC can be coupled with a sampler that collects the particles for further analysis. See [0167]. The Specification further teaches that as part of a program to develop continuous sensors for nerve agent vapors, continuous enzymatic sensing chemistries have been previously developed by the Applicant that demonstrated detections as low as 0.25-1.4 μg/m3 of nerve agents, equating to sub-ppb detection limits, within two minutes-an unprecedented level of detection for these highly toxic chemical threats (the IBAC model and representative detection signal are shown in FIG. 14A and FIG. 14B), and that the present technology leverages this same approach and hardware to provide sensitive, real-time fluorescent assays that detect viral aerosols, enabling rapid, non-contact detection and identification. See [0168]. However, the Specification does not show evidence that the described devices can be used in the detection of virus particles in an air sample using the method as claimed.
It is known in the art that samplers are used to collect and/or enrich virus particles from air samples, producing test samples that contain not only sufficient amount virus particles but also in a proper form (e.g., a liquid or hydrosol form) for the succeeding detections. See discussions in the art rejections below. The invention as claimed does not require such an aerosol to liquid or hydrosol transition to facilitate binding of the target virus particles to the bind agent as well as the following reporter binding and detection steps. Neither the Specification nor knowledge in the art has evidence that virus particles in an aerosol sample can be successfully detected by a binding assay without a sample collection step that enriches and transforms the aerosol sample to a liquid or hydrosol test sample. The Specification discusses about detection of general particles or nerve agent in air samples with the existing devices (e.g., IBAC, see discussion above), but does not provide sufficient information about those devices and how they can be used in the detection of virus particles based on the invention as claimed.
Claims 5-6 specify that the binding agent may comprise a lectin, and more specifically, a Griffithsin peptide, without sufficient guidance on how a lectin peptide could be put on a support for binding the target virus in order to facilitate detection of virus particles in an air sample, giving that lectins are not virus-specific. Claims 8-15 specify various potential reporters, such as substrate for an enzyme, or labeled lectin or antibody. The Specification does not give sufficient guidance on how such potential reporter molecules can be used on what virus types in a detection method according to the claims, nor does the Specification show evidence that such potential reporter molecules have worked in a process according to the claims.
In summary, the Specification describes a generic invention for detecting virus in an air sample by putting together various elements known in the art of virus detection. However, the Specification does not provide sufficient evidence that such a combination of elements actually works in a process according to the claims, nor does it provide sufficient guidance on how the combination of the art-known elements can be reduced to practice as claimed, especially considering the hurdles for detecting virus particles in the air that artisans in the field are making efforts trying to overcome.
Accordingly, the specification does not provide written description support that the Applicant is in possession of the invention in the generic form as claimed.
Claim Rejections - 35 USC § 112(a) (Scope of Enablement)
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.
Claims 1-19 are rejected under 35 U.S.C. 112(a), because the specification, while being enabling for detecting a virus in an air sample after collecting and/or concentrating virus particles in the air sample in a liquid/hydrosol carrier before contacting with a binding agent, does not reasonably provide enablement for detecting a virus by contacting an air sample directly to a binding agent without the requirement of sample collection, enrichment and transition into liquid or hydrosol form, which is routinely required for binding assays in the detection of virus particles in air samples (see art rejections below). The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to practice the invention commensurate in scope with these claims.
To be enabling, the specification of the patent must teach those skilled in the art how to make and use the full scope of the claimed invention without undue experimentation. In re Wriqht, 999 F.2d 1557, 1561 (Fed. Cir. 1993). Explaining what is meant by "undue experimentation," the Federal Circuit has stated:
The test is not merely quantitative, since a considerable amount of experimentation is permissible, if it is merely routine, or if the specification in question provides a reasonable amount of guidance with respect to the direction in which the experimentation should proceed to enable the determination of how to practice a desired embodiment of the claimed invention. PPG v. Guardian, 75 F.3d 1558, 1564 (Fed. Cir. 1996).1
The factors that may be considered in determining whether a disclosure would require undue experimentation are set forth by In re Wands, 8 USPQ2d 1400 (CAFC 1988) at 1404 where the court set forth the eight factors to consider when assessing if a disclosure would have required undue experimentation. Citing Ex parte Forman, 230 USPQ 546 (BdApls 1986) at 547 the court recited eight factors:1) the quantity of experimentation necessary, 2) the amount of direction or guidance provided, 3) the presence or absence of working examples, 4) the nature of the invention, 5) the state of the prior art, 6) the relative skill of those in the art, 7) the predictability of the art, and 8) the breadth of the claims. Id. While it is not essential that every factor be examined in detail, those factors deemed most relevant should be considered.
M.P.E.P. §2164.03 [R-2] states: [I]n applications directed to inventions in arts where the results are unpredictable, the disclosure of a single species usually does not provide an adequate basis to support generic claims. In re Soil, 97 F.2d 623,624, 38 USPQ 189, 191 (CCPA 1938). In cases involving unpredictable factors, such as most chemical reactions and physiological activity, more may be required. In re Fisher, 427 F.2d 833,839, 166 USPQ 18, 24 (CCPA 1970). See also In re Wright, 999 F.2d 1557, 1562, 27 USPQ2d 1510, 1513 (Fed. Cir. 1993); In re Vaeck, 947 F.2d 488,496, 20 USPQ2d 1438, 1445 (Fed. Cir. 1991). A conclusion of lack of enablement means that, based on the evidence regarding each of the above factors, the specification, at the time the application was filed, would not have taught one skilled in the art how to make and/or use the full scope of the claimed invention without undue experimentation. In re Wright, 999 F.2d 1557,1562, 27 USPQ2d 1510, 1513 (Fed. Cir. 1993).
The nature of the invention is a method for detecting virus comprising contacting a virus-including air sample with a binding agent on a support, followed by contacting the virus particles bound to the binding agent on the support with a reporter that specifically binds to and/or is cleaved specifically by a surface protein of the bound virus particles, and detection of the reporter.
As indicated in the 112(a) written description rejection above, the Specification describes in high generality an invention for detecting virus in an air sample based on basic virus biology, assay chemistry, and processes in the detection of viruses by putting together various elements known in the field of virus detection. However, the Specification does not provide sufficient evidence that such a combination of elements actually works in a process according to the claims, nor does it provide sufficient guidance on how the combination of art-known elements can be reduced to practice in an invention as claimed.
The state of the art is discussed in the art rejection below. There are hurdles for detecting virus particles in an air sample that artisans in the field have made great efforts trying to overcome, especially considering the requirement of sample collection for virus particle enrichment as well as transiting the sample’s aerosol form into a liquid or hydrosol form for the claimed binding assays. The invention as claimed specify contacting an air sample directly to a binding agent without the requirement of sample collection, enrichment and transition into liquid or hydrosol form, that is commonly required for binding assays in the detection of virus particles in air samples. See discussions in the art rejection below. The breadth of the claims is wide, encompassing any virus, any binding agent, any support, any reporter and any detecting means. The relative skill of those in the art is high, requiring deep and broad understanding of virus biology, assay chemistry, assay development, aerosol properties, as well as device development techniques. Neither the Specification nor art of the field show evidence that a working example exists that can successfully detect a virus in an air sample using a process according to the claims, without going through an extra step of sampling and/or phase transition (aerosol to hydrosol). Thus, the predictability of the art is low.
Therefore, the specification does not provide sufficient guidance to allow one skilled in the art to practice the claimed invention on the full scope with a reasonable expectation of success and without undue experimentation. In the absence of such guidance and evidence of working examples, the specification fails to provide an enabling disclosure commensurate in scope with the claim.
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 of this title, 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 1-4, 7-8, 12-14 and 16-19 are rejected under 35 U.S.C. 103 as being unpatentable over Bhardwaj et al. (Environ. Sci. Technol. 2020, 54, 10700−10712; of record in the previous Office action) and Kabir et al. (ACS Sens., 2020, 5, 1254−1267; of record in the previous Office action).
The base claim 1 is directed to a method for detecting a virus, the method comprising:
contacting an air sample including virus particles with a binding agent on a support, thereby binding at least a portion of the virus particles in the air sample to the binding agent on the support;
contacting the virus particles bound to the binding agent on the support with a reporter that binds specifically to and/or is cleaved specifically by a surface protein of the virus particles or a glycoprotein of the virus particles; and
detecting the presence of the reporter bound to and/or cleaved by the surface protein of the virus particles or the glycoprotein of the virus particles.
Bhardwaj teaches a study on detection of airborne influenza virus using an antibody-based electrochemical paper sensor and electrostatic particle concentrator. Bhardwaj teaches that vertical-flow-assay-based electrochemical paper immunosensors were fabricated to rapidly quantify the influenza H1N1 viruses in air after sampling with a portable electrostatic particle concentrator (EPC). The effects of antibodies, anti-influenza nucleoprotein antibodies (NP-Abs) and anti-influenza hemagglutinin antibodies (HA-Abs), on the paper sensors as well as nonpulsed high electrostatic fields with and without corona charging on the virus measurement were investigated. The antigenicity losses of the surface (HA) proteins were caused by H2O2 via lipid oxidation-derived radicals and 1O2 via direct protein peroxidation upon exposure of a high electrostatic field. However, minimal losses in antigenicity of NP of the influenza viruses were observed, and the concentration of the H1N1 viruses was more than 160 times higher in the EPC than the BioSampler upon using NP-Ab based paper sensors after 60 min collection. This NP-Ab-based paper sensors with the EPC provided measurements comparable to quantitative polymerase chain reaction (qPCR) but much quicker, specific to the influenza H1N1 viruses in the presence of other airborne microorganisms and beads, and more cost-effective than enzyme-linked immunosorbent assay and qPCR. See Abstract.
Bhardwaj teaches that airborne influenza viruses were collected using an electrostatic field in the study; hence, damage to the influenza viruses that may occur under an electrostatic field can significantly affect their detection using antibody-based immunosensors, thus requiring information on which part of influenza viruses are intact during electrostatic sampling. The use of antibody-functionalized paper sensors can demonstrate the extent of the damage, which has not been explored before and would be critical for rapid quantification of airborne viruses via antigen−antibody affinity. See page 10702, right column, para 2.
For the viral aerosol generation and collection, Bhardwaj teaches that the influenza A H1N1 virus suspension (106 PFU mL−1) prepared in deionized (DI) water was nebulized using a three-jet Collison nebulizer (Mesa Laboratories, Denver, CO) with 3.0 L/min (LPM) (at ∼7 psi) of clean air. The viral aerosols were passed through a diffusion dryer (HCT, South Korea) and a neutralizer (model 5.622, GRIMM, Germany), diluted with 10 LPM of clean air, and then guided into the EPC. After placing 0.5 mL of 1× phosphate buffered saline (PBS), which was used as a collection medium in all experiments, on the collection electrode of the EPC, the viral aerosols were collected at 1.2 LPM at an applied voltage of −5 kV corresponding to 1.56 × 105 V/m, where the electric field intensity is based on the shortest horizontal distance (32 mm) between the collection electrode and the side wall, with corona charging (3.0 kV). The BioSampler was also operated at 12.5 LPM to collect the airborne virus particles into 20 mL of the same medium. The EPC and the BioSampler were operated for various sampling durations ranging from 2 to 60 min. The virus concentrations of the collection media of both samplers were measured based on the same virus concentration in air at 13 LPM, and the media were not refilled over 60 min, which can decrease the collection efficiency of the BioSampler. After sampling for 2−60 min, the media were stored at 4 °C until further analysis. The particle size distributions were measured at the outlet of the EPC using a scanning mobility particle sizer (model 5.416, GRIMM, Germany) without corona charging and electric biases to the EPC. See page 10703, left column, para 1.
For the analysis of collected/sampled viruses, Bhardwaj teaches that paper-based electrochemical sensors were fabricated. The measurement of viral concentrations with the paper sensors was achieved using two types of capture antibodies based on the HA proteins (anti-HA monoclonal (mAb) and polyclonal (pAb) antibodies) (mAb1, SAB1411734; mAb2, MA5-15784; pAb, PA5-34929) (Sigma-Aldrich, U.S.) and NP (Influenza A NP monoclonal antibody (mAb), OBT1557, AbD Serotec, U.S.) of the influenza virus. For NP-Ab based detection, 10 μL of 0.5% Triton-X (T93443, Sigma-Aldrich) was added to the collected virus samples (0.5 mL) and incubated at 25 °C for 5 min. Then, 40 μL of the lysed sample was transferred to the inlet of the paper sensor using a pipet (Figure 1). The viruses started to flow vertically for binding with the horseradish peroxidase (HRP) tagged NP-mAb (AB176837, Abcam, UK) on a conjugate pad (G041, Millipore, Billerica, MA) for 2 min. Subsequently, 100 μL of PBS was applied through the sensor inlet to continue the flow of viruses-HRP tagged NP-Ab complexes from the conjugate pad to the nitrocellulose membrane (10600002, General Electric Healthcare, South Korea) and incubated for an additional 4 min. The viruses-HRP tagged NP-Ab complexes bound with the NP-Ab functionalized gold electrode on the membrane. For HAAbs (mAb1, mAb2, and pAb) based detection, the samples collected on the EPC were transferred to the paper sensors without treatment with 0.5% Triton-X, and HRP tagged HApAb (60-130, Fitzgerald, U.S.) was used on the conjugate pad. See page 10703, left column, para 2.
Kabir reviews advances in monitoring, sampling, and sensing techniques for bioaerosols in the atmosphere. It teaches that bioaerosols in the form of microscopic airborne particles pose pervasive risks to humans and livestock. As either fully active components (e.g., viruses, bacteria, and fungi) or as whole or part of inactive fragments, they are among the least investigated pollutants in nature. Their identification and quantification are essential to addressing related dangers and to establishing proper exposure thresholds. See Abstract.
Kabir presents a schematic picture of a general flow of a process for detection of bioaerosols, including sampling and sensing. See below:
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Figure 2 presents a general flow of bioaerosol detecting process. See below:
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Kabir teaches that sampling and monitoring methods for bioaerosol detection can be divided into direct sensing and conventional approaches. The former includes simultaneous sampling followed by sensing, and the latter involves discrete allocation between the sampling and analysis. See page 1256, right column, para 4. Kabir further teaches that sensing methods for bioaerosol or airborne pathogen detection include immunosensing methods and non-immunosensing methods. The former is based on antibody-antigen interactions (see Table 1) while the latter may be based on nanoparticles (see Table 2).
Accordingly, Bhardwaj and Kabir teach methods of detecting airborne virus particles wherein virus particles in aerosols were collected (sampled) by a sampler, and that the collected (sampled) virus particles were further detected by contacting with a binding agent that specifically binds the virus particles (e.g., virus-specific antibodies) and a reporter (e.g., HRP). However, neither Bhardwaj nor Kabir teaches directly contacting an air sample including virus particles with a binding agent on a support. Instead, Bhardwaj and Kabir teach detection of airborne viruses by first collecting virus particles in the air with a sampler, then contacting the collected sample to binding agents (e.g., viral-specific antibodies) on a support. This extra step is expected to increase the number of viral particles to ensure success of the succeeding detections.
It would have been prima facie obvious for one of ordinary skill in the art before the effective filing date of the current invention to omit the sampling/collecting step with a sampler, as taught in Bhardwaj and Kabir, and arrive at the invention as claimed. One would have been motivated to do so to simplify the detection process, if there exists a detection technique having a high enough sensitivity to detect unsampled virus particles directly in an air sample. Omission of an Element and Its Function Is Obvious if the Function of the Element Is Not Desired. See MPEP 2144.4 IIA. Here, the step of sample collection with a sampler, taught in Bhardwaj and Kabir, has an obvious function, and can be considered as not desired, if a detection technique exists having a high enough sensitivity to detect virus particles directly in an air sample.
Regarding claim 7, the support can be considered as any solid surface that can be used to hold a binding agent suitable for catching virus particles from an air sample based on the experimental device designed by a skilled artisan, including a microplate which is routinely used in the studies involving immune assays.
Regarding claims 8 and 12-14, both Bhardwaj and Kabir teach detection of virus antigens with various immunoassays, which involve labeled antibodies as well as fluorescent dyes. One of skill in the art would have found it obvious to apply immunoassay reagents and techniques known in the art at the time of invention to facilitate a virus detection method as claim. See Discussions above.
Claims 1-4, 6-8, 12-14 and 16-19 are rejected under 35 U.S.C. 103 as being unpatentable over Bhardwaj et al. (Environ. Sci. Technol. 2020, 54, 10700−10712; of record in the previous Office action), Kabir et al. (ACS Sens., 2020, 5, 1254−1267; of record in the previous Office action), Kim et al. (Biosensors and Bioelectronics 170 (2020) 112656, available online 26 September 2020; submitted in IDS filed on Jun 9, 2023), and Barre et al. (Mar. Drugs 2020, 18, 543).
Claims 1-4, 7-8, 12-14 and 16-19 are described above. Claims 4-6 further specify that the binding agent may be a lectin, and more specifically, Griffithsin.
Relevance of Bhardwaj and Kabir is set forth in the 103 rejection above. Briefly, they teach methods of detecting airborne virus particles wherein virus particles in aerosols were collected (sampled) by a sampler, and that the collected (sampled) virus particles were further detected by contacting with a binding agent that specifically binds the virus particles (e.g., virus-specific antibodies) and a reporter (e.g., labeled antibodies).
Kim discloses an integrated system of air sampling and simultaneous enrichment for rapid biosensing of airborne coronavirus and influenza virus. Kim teaches that Point-of-care risk assessment (PCRA) for airborne viruses requires a system that can enrich low-concentration airborne viruses dispersed in field environments into a small volume of liquid. In this study, airborne virus particles were collected to a degree above the limit of detection (LOD) for a real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). This study employed an electrostatic air sampler to capture aerosolized test viruses (human coronavirus 229E (HCoV-229E), influenza A virus subtype H1N1 (A/H1N1), and influenza A virus subtype H3N2 (A/H3N2)) in a continuously flowing liquid (aerosol-to-hydrosol (ATH) enrichment) and a concanavalin A (ConA)-coated magnetic particles (CMPs)-installed fluidic channel for simultaneous hydrosol-to-hydrosol (HTH) enrichment. The air sampler’s ATH enrichment capacity (EC) was evaluated using the aerosol counting method. In contrast, the HTH EC for the ATH-collected sample was evaluated using transmission-electron-microscopy (TEM)-based image analysis and real-time qRT-PCR assay. For example, the ATH EC for HCoV-229E was up to 67,000, resulting in a viral concentration of 0.08 PFU/mL (in a liquid sample) for a viral epidemic scenario of 1.2 PFU/m3 (in air). The real-time qRT-PCR assay result for this liquid sample was “non-detectable” however, subsequent HTH enrichment for 10 min caused the “non-detectable” sample to become “detectable” (cycle threshold (CT) value of 33.8 ± 0.06). See Abstract.
Kim teaches that developing a point-of-care risk assessment (PCRA) system to enrich the low-concentration airborne viruses scattered in field environments into a small volume of liquid to a concentration above the LOD of real-time qRT-PCR is vital for preventing fatalities from airborne viruses and stopping their spread. Accordingly, an aerosol-to-hydrosol (ATH) enrichment capacity (EC) of 105–106-fold (from 103–104 of viral genome copies per 1 m3 of air in a viral epidemic scenario to 103 of viral genome copies per 1 mL of liquid) is required. For high EC, a high viral collection efficiency with a high air-sampling flow rate and small volume of the liquid sample are essential. See page 2, left column, para 2.
Kim teaches that it is practically difficult for an air sampler to meet all these requirements for a high EC. For example, the Airborne Sample Analysis Platform (ASAP) 2800 (Thermo Scientific, USA) bioaerosol sampler is a commercial device that cannot collect airborne particles smaller than 1 μm, which accounts for 20–60% of the indoor airborne particles that contain viruses (Thermo scientific; Yang et al., 2011). Lee et al. (2016) reported a disposable bio-precipitator for capturing and enriching airborne bacteria into small volume of liquid (15 μL). The National Institute for Occupational Safety and Health (NIOSH) bioaerosols sampler was developed to sample virus-containing particles smaller than 1 μm. However, an additional recovery step is required for bioassaying because the NIOSH bioaerosols sampler collects airborne particles smaller than 1 μm on a filter (Cao et al., 2011). The SKC BioSampler is a commercial air-sampling device that captures bioaerosols in 20 mL of liquid such that the liquid sample can be easily used in a bioanalytical assay. However, its EC is only 62.5, which is inappropriate for use in field environments. The low collection efficiency for virus-sized particles (100 nm) and the relatively large volume of collection liquid (20 mL) for the SKC BioSampler results in a low EC (Hogan et al., 2005). See page 2, left column, para 3.
Kim teaches that lab-designed air samplers have been developed for a higher enrichment capacity (EC). Wubulihairen et al. (2015) introduced an ATH sampler that could apply an inertia impaction method where the EC was 835 for 100-nm particles. Hong et al. (2016) studied an electrostatic particle concentrator (EPC) that could capture airborne viruses in a liquid volume of 0.5 mL; however, the EPC had a low EC of 8750 for a 100-nm airborne virus. See page 2, left column, para 4.
Kim teaches that the authors have developed a field-applicable system to address these challenges (high viral collection efficiency with a high air-sampling flow rate and a small volume of liquid sample for high EC) that collects airborne viruses in a liquid and simultaneously enriches the collected viruses above the LOD of a real-time qRT-PCR device. They have previously reported a method for ATH sampling and the simultaneous HTH enrichment of airborne bacteria (Kim et al., 2020). An electrostatic air sampler and an enrichment channel immobilized with concanavalin A (ConA)-coated magnetic particles (CMPs) were applied to achieve a high EC. With this method, the low-concentration aerosolized Staphylococcus aureus (4.75 × 106 CFU per 1 m3 of air, CFU: colony-forming unit) bacteria were converted into highly enriched bacteria (5.66 × 106 CFU per 1 mL of liquid). See page 2, left column, para 5.
Kim teaches that their method is expanded for airborne viruses with a system that integrates an ATH sampler and a HTH enrichment channel. Even though a liquid sample obtained via the ATH collection of virus particles of very low concentration in air is “non-detectable” in real-time qRT-PCR analysis, they demonstrate that subsequent HTH enrichment can cause a “non-detectable” sample to become “detectable.” Human coronavirus 229E (HCoV-229E), Influenza A virus subtype H1N1 (A/H1N1), and Influenza A virus subtype H3N2 (A/H3N2) were used as test viruses. The ATH enrichment capacities of the viruses were evaluated using an aerosol counting method. Transmission electron microscopy (TEM) and real-time qRT-PCR were applied for the reliable verification of HTH EC. See page 2, left column, para 6.
Fig. 1 of Kim shows the experimental setup. See below:
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Accordingly, Kim teaches a study employing an electrostatic air sampler to capture aerosolized test viruses via an aerosol-to-hydrosol (ATH) enrichment and a concanavalin A (ConA)-coated magnetic particles (CMPs)-installed fluidic channel for a hydrosol-to-hydrosol (HTH) enrichment, before virus particles are further detected by succeeding processes. Here, ConA is a lectin and is used as a binding agent that binds to virus particles with glycoproteins on the surface.
Barre teaches that seaweed lectins, especially high-mannose-specific lectins from red algae, have been identified as potential antiviral agents that are capable of blocking the replication of various enveloped viruses like influenza virus, herpes virus, and HIV-1 in vitro. The diversity of glycans present on the S-glycoproteins forming the spikes covering the SARS-CoV-2 envelope, essentially complex type N-glycans and high-mannose type N-glycans, suggests that high-mannose-specific seaweed lectins are particularly well adapted as glycan probes for coronaviruses. See Abstract.
Barre teaches that the man-specific lectin griffithsin (GRFT) of the red alga Griffithsia sp., readily recognized the high mannose N-glycans located on the very similarly glycosylated SARS-Co V S-glyco- protein. More generally, in agreement with their capacity to specifically recognize high- mannose glycoprotein targets exposed at the surface of enveloped viruses, e.g., hemagglutinin of influenza virus, gpl20 of HIV-1 or the spike S-glycoprotein of SARS-CoV and SARS-CoV-2, Man-specific seaweed lectins can interfere with the mechanisms allowing the infectious viruses to recognize the corresponding receptors and trigger the fusion events necessary for entering the susceptible cells. See para bridging pages 17 and 18.
Accordingly, Barre teaches Griffithsin (GRFT), a red algae lectin, that binds to surface glycoprotein of some enveloped viruses, including influenza viruses and SARS-CoV-2.
It would have been prima facie obvious for one of ordinary skill in the art before the effective filing date of the current invention to combine the teachings of Bhardwaj, Kabir, Kim and Barre to arrive at the invention as claimed. First, one would have been motivated to do so to simplify the process of detecting virus particles in an air sample by omitting the sample collection step with a sampler, a step taught in Bhardwaj, Kabir and Kim for the collection and enrichment virus particles in an air sample, if there exists a detection technique having a high enough sensitivity to detect unconcentrated virus particles directly in an air sample. Omission of an Element and Its Function Is Obvious if the Function of the Element Is Not Desired. See MPEP 2144.4 IIA. Here, the step of sample collection with a sampler, taught in Bhardwaj, Kabir and Kim, has an obvious function and can be considered as not desired, if a detection technique exists having a high enough sensitivity to detect virus particles directly in an air sample. Secondly, one of skill in the art would have been motivated to include a virus-binding step with lectin, such as the ConA or Griffithsin, taught in Kim and Barre, in addition to or in place of the antibody-binding steps taught in Bhardwaj and Kabir, to catch and enrich virus particles from an air sample to facilitate the succeeding detection process.
Conclusion
No claims are allowed.
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/NIANXIANG ZOU/
Primary Examiner, Art Unit 1671