DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 09/26/2025 has been entered.
Status of Claims
Claims 1-2, 5-6, 10-15 remain pending in the application, with claims 1-2, 5-6, 10 being examined and claims 11-15 being withdrawn pursuant to the election filed 06/07/2021.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-2, 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lee (US-2013/0052649-A1) in view of Chang (WO-2017/185098-A1), Collins (US-2016/0167051-A1), Hansen (US-5508197-A), Kobayashi (US-2007/0144253-A1) and Cooney (US-2017/0016052-A1).
Regarding claim 1, Lee teaches a microfluidic system for digital polymerase chain reaction (dPCR) of a biological sample, the microfluidic system comprising:
at least one microfluidic device (multilayer well device 10) having an inlet (inlet 26), an outlet (outlet 28), a flow channel (common channel 24) connecting the inlet (26) to the outlet (28), and an array of dPCR reaction areas (array of wells 22) provided within the flow channel (24), and wherein the array of dPCR reaction areas (22) comprises an array of microwells ([0021] describes an array of wells 22), wherein each microwell (22) has an opening width ranging from 60 µm to 110 µm and a cross-sectional area with a hexagonal shape ([0021], [0024], [0026] see wells in the shape of hexagons, [0033] describes Figure 6A that shows where device has octagonal-shaped microwell arrays with a 70 µm diameter where it is understood the hexagon shaped wells may similarly have a 70 µm diameter, Figures 1A-B, 2A-D);
a sample liquid source connectable to the microfluidic device (10), for providing the microfluidic device (10) with a sample liquid ([0029] describes that the wells are filled with an aqueous fluid which contains the cells, organelles or other biological constituents for imaging, where it is understood that this is a liquid source that is connectable to the device 10);
an optical detection device (imaging device 40) for detecting the presence or generation of one or more gas bubbles in the microfluidic device (10) ([0030] see where the imaging device 40 may include a microscope or the like, Figure 5);
It is noted that the limitation “an optical device for detecting the presence or generation of one or more gas bubbles in the microfluidic device” is directed to the intended use of the optical detection device that does not provide additional structure. All the structural limitations of the optical detection device have been disclosed by Lee and the imaging device of Lee is capable of detecting the presence or generation of gas bubbles in the microfluidic device. As such, it is deemed that the claimed optical detection device is not differentiated from the imaging device of Lee (see MPEP §2114).
a primary sealing liquid source connectable to the microfluidic device (10), for providing the microfluidic device (10) with initial sealing liquid for sealing the sample liquid inside the array of reaction areas (22) ([0029] describes where following filling the wells, an immiscible second fluid such as a light-mineral oil is injected, it is understood that this is a primary sealing liquid source connectable to the device 10 for providing the device 10 with initial sealing liquid);
a secondary sealing liquid source connectable to the microfluidic device (10), for providing the microfluidic device (10) with additional sealing liquid (it is understood that the immiscible second fluid described by [0029] is also a secondary sealing liquid source that will provide the device 10 with additional sealing liquid),
Lee does not teach:
wherein the flow channel comprises a width ranging from 6 mm to 7 mm,
In the analogous art of micro-well chips, Chang teaches where a micro-well chip includes a thin plate having a surface with one or more arrays of micro-wells (Chang; [0006]).
Specifically, Chang teaches a micro-well chip 110 has multiple surfaces that form a microfluidic chamber where fluid sample flows between an inlet port and an outlet port, where the bottom surface of the microfluidic chamber includes or contains a plate that includes an array of micro-wells that is designed to capture individual cells or cell clusters suspended in the fluid sample (Chang; [0090]). Further, [0142] of Chang describes Figures 3A- B where there is base 310 that includes micro-wells, a spacer 320 and a top plate 330 that are stacked on the base 310 to create a space between the surface 310a of the base 310 and top plate 330 that corresponds to a microfluidic chamber. [0149] of Chang describes where the length and width of the fluidic chamber may range from 100 μm to 20 cm.
Lee is silent with regards to specific width of the common channel, therefore, it would have been necessary and thus obvious to look to the prior art for conventional multilayer well devices. Chang provides this conventional teaching showing that it is known in the art to have a chamber with a width of 100 μm to 20 cm. Therefore, it would have been obvious to one having ordinary skill in the art to make the common channel 100 μm to 20 cm because it is taught by Chang that this width is effective for micro-well chips that have media flow through it and capture cells in the wells.
Chang does not teach where flow channel comprises a width ranging from 6 mm to 7 mm. However, there is no established criticality or evidence showing an unexpectedly good result occurring form the claimed parameters. Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to 6 mm to 7 mm, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Further, it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. MPEP 2144.05.II.
It is understood that a length of the device 10 of Lee is between the inlet and outlet seen in Figure 1B, where the width of the common channel 24 will be the dimension perpendicular to the length. Further, as the device of modified Lee meets the structural limitations of the microwells and flow channel, it is understood that 60 to 100 microwells would be capable of fitting in a lateral direction of the flow channel.
Lee does teach where the multilayer well device 10 can be used in polymerase chain reaction applications (Lee; [0029]), however Lee does not teach:
a flow circuit connectable to the microfluidic device, for flowing liquid through the flow channel of the microfluidic device;
the secondary sealing liquid source comprising a first reservoir with a heated supply of the additional sealing liquid and a second reservoir with a non-heated or cooled supply of the additional sealing liquid, each of said first and second reservoirs being separately connected to the flow circuit by respective electronically controlled delivery valves, and
a pumping device connected to the flow circuit and comprising a control unit, the pumping device further being configured to maintain a desired temperature profile for thermocycling the sample liquid in the reaction areas by pumping the additional sealing liquid from at least one of the first reservoir and the second reservoir through the flow channel to provide heat or cold to the array of reaction areas.
In the same problem solving area of thermocycling for fast and reliable PCR reactions, Collins teaches rapid thermal cycling on anchored single droplets at micropillar trapping sites (Collins; [0023], [0025]).
Specifically, Collins teaches where single cell trapping sites seen in Figure 25 are six square micropillars so that a cell can enter and get trapped while fluid flows away, where Figure 26 shows a fluidic manifold for holding the PILLAR chip and flow based thermal cycling using a set of valves and pumps (Collins; [0122]). As further described by [0130], the chip performs five steps: (1) microarray spotting of multiple primer pairs, (2) flow based single-cell trapping using micropillars, (3) flow of immiscible fluid for forming picoliter reactors, (4) convection driven thermal cycling for PCR, (5) fluorescence imaging based quantification and deletion analysis. The fluidic manifold has two oil baths, valves, and a pump for oil delivery into the disposable chip, where in order to perform PCR thermal cycling, oil from isolated hot and cold baths is heated to 95 degrees C and 50 degrees C and is circulated into entrapped droplets alternately using the pump (Collins; [0130]). It is further described by [0131] that a system includes a flow device, fluorescence detection, thermal cycler, and software control systems, where the software controls the timing of the thermal cycling.
It would have been obvious to one skilled in the art to modify the multilayer well device of Lee such that it includes the manifold and software control as taught by Collins, because it is taught by Hansen that having tanks at maintained temperatures allows for an increase in the rapidity of temperature switching, where if heat transfer to reagents is slow it increases the overall cycling time as well as subjecting biological reagents to intermediate non-ideal temperatures that can lead to nonspecific priming and the amplification of undesired DNA (Hansen; column 2 lines 48-61, column 12 lines 22-25).
Further, Lee is silent with regards to specific ways for thermal cycling the device when used in PCR applications, therefore, it would have been necessary and thus obvious to look to the prior art for conventional means for thermal cycling. Collins provides this conventional teaching showing that it is known in the art to use a manifold to deliver oil at different temperatures for thermal cycling. Therefore, it would have been obvious to one having ordinary skill in the art to modify the second immiscible oil-based second fluid of Lee such that there are reservoirs of immiscible oil set at different temperatures connected to the device by a manifold because it is taught by Collins that this is an effective way to rapidly thermal cycle samples.
It is understood that there is a fluidic connection between the fluidic manifold and the chip, where there will be a similar connection between the fluidic manifold and the multilayer well device of Lee, where this connection will be the flow circuit. The software control system will control the fluidic manifold to supply oil for a profile of thermocycling.
While Lee does teach an imaging device, and there is now the software control system of Collins that controls thermal cycling, Lee nor Collins teach wherein the control unit is configured to cause the pumping device to pump said additional sealing liquid through the flow channel on demand to flush the one or more gas bubbles present in at least one of the sample liquid and the sealing liquid out of the flow channel when said optical detection device detects the presence or generation of the one or more gas bubbles in at least one of the sample liquid and the sealing liquid in the microfluidic device,
In the same problem solving area of eliminating air bubbles, Kobayashi teaches a syringe pump that has detectors to detect air bubbles (Kobayashi; [0035]).
Specifically, Kobayashi teaches where bubble detectors 65 and 66 can be disposed in liquid channels, including tubes 58 and 59, where the detectors can detect air bubbles in water either optically or physically (Kobayashi; [0035], Figure 5). It is further stated by [0035] of Kobayashi that when a detector detects air bubbles, water is fed into the tubes 58 and 59 until the air bubbles are eliminated. It is described in an alternative embodiment of Kobayashi that there is a controller 17 that controls motor 25 of the pump driver 12, where when probe tip 14a reaches the liquid surface, the liquid surface detector 18 outputs a liquid surface detection signal that causes the controller 17 to control the probe moving section 15 to stop the suction probe (Kobayashi; [0021], Figure 1). A controller is not seen in Figure 5 of Kobayashi, however it is understood that there would need to be a controller present to both coordinate the various components seen in Figure 5 of Kobayashi, including: the pump driver 12, suction probe 14, detectors 65 and 66, and pump 63 (Kobayashi; [0035]).
It would have been obvious to one skilled in the art to modify the software control system of Collins to connect it to imager of Lee, such that when air bubble is detected it would cause fluid to be fed through the channels to eliminate air bubbles because it is taught by Cooney that air bubbles can cause unpredictable behavior of fluid flow in microfluidic devices, clog channels, interfere with biochemical reactions, and interfere with optical reads (Cooney; [0003]).
Regarding claim 2, modified Lee teaches the microfluidic system of claim 1. Lee further teaches wherein each of the initial and additional sealing liquid is an immiscible liquid (Lee; [0029]).
Regarding claim 6, modified Lee teaches the microfluidic system of claim 1. Lee further teaches further comprising one or more of the following:
(a) the microfluidic system is used for assaying said biological sample provided in the form of said sample liquid to each microwell of the array of reaction areas (Lee; [0029] see the fluorescent stain may be used for performing biochemical or biological reaction or assays);
It is noted that the limitations of b, c, and d are not required due to recitation of “comprising one or more of the following”. However, it is noted that Lee further teaches:
(b) the inlet and/or the outlet are implemented in the form of a connection port for connection of the microfluidic device with the sample liquid source, for connection of the microfluidic device with the primary sealing liquid source, and/or for connection of the microfluidic device with the secondary sealing liquid source (Lee; [0027] describes where holes are punched to form the inlet 26 and outlet 28, [0029] describes where a first fluid is flowed into the inlet 26 and then second immiscible oil-based second fluid is injected behind the first fluid);
(c) the microfluidic device is structured with at least a bottom layer and a top layer, wherein either said bottom layer or said top layer provides the array of reaction areas, the inlet and the outlet, and wherein the flow channel is established between said bottom layer and said top layer and is in fluid connection with the array of reaction areas (Lee; [0021], [0024], Figures 1A-B); and
(d) the sample liquid is an aqueous solution comprising said biological sample and reagents required for dPCR assay, wherein first the sample liquid is streamed through the flow channel into the array of reaction areas, and wherein the initial sealing liquid is streamed into the flow channel of the microfluidic device after the provision of the sample liquid to the array of reaction areas (Lee; [0029] describes where the first fluid is an aqueous fluid that contains the cells, organelles, or other biological constituents for imaging, where the device can be used in PCR applications as well, it is understood that for PCR applications it would therefore have reagents required for PCR. [0029] of Lee further describes where the wells are first filled with the first fluid, and then the second immiscible oil-based second fluid is injected behind the first fluid).
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lee (US-2013/0052649-A1), Chang (WO-2017/185098-A1), Collins (US-2016/0167051-A1), Hansen ((US-5508197-A), Kobayashi (US-2007/0144253-A1) and Cooney (US-2017/0016052-A1), and in further view of Borden (US-2012/0175305-A1).
Regarding claim 5, modified Lee teaches the microfluidic system of claim 1. Lee does not teach wherein the microfluidic system further comprises a bubble trap connected to the flow circuit to separate the one or more gas bubbles from the initial sealing liquid, wherein the bubble trap is arranged downstream of the outlet of the microfluidic device.
In the same problem solving area of bubble removal from a solution, Borden teaches a recycling device that removes bubbles.
Specifically, Borden teaches that a bubble trap may be used to remove bubbles from a solution that will be recycled (Borden; [0041]). As it is understood, the bubble trap will be placed after the post-processing block 108 as seen in Figure 1 of Borden. Therefore, it is understood that the bubble trap will be downstream of an outlet.
It would have been obvious to one skilled in the art to modify the device of Lee such that it includes a bubble trap downstream of the outlet as taught by Borden for the benefit of removing bubbles such that the solution may be recycled (Borden; [0041]).
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lee (US-2013/0052649-A1), Chang (WO-2017/185098-A1), Collins (US-2016/0167051-A1), Hansen ((US-5508197-A), Kobayashi (US-2007/0144253-A1) and Cooney (US-2017/0016052-A1), and in further view of Fradet (WO-2016/170126-A1).
Regarding claim 10, modified Lee teaches the microfluidic system of claim 1. Lee does not teach wherein the microfluidic system further comprises a pressure chamber surrounding at least the microfluidic device.
In the same problem solving area of filling a microfluidic device with a sample, Fradet teaches a pressure chamber (Fradet; abstract).
Specifically, Fradet teaches a pressure chamber 1 that holds a microfluidic device 2 inside, where the microfluidic device has ports 3 and 4, and a microchannel network 5 (Fradet; Page 49 lines 18-22). As stated by page 3 lines 13-17 of Fradet, there is a pressure chamber that has a closable aperture, and is configured to enclose a microfluidic device and a pressurization unit that applies pressure to the pressure chamber.
It would have been obvious to one skilled in the art to modify the device of Lee such that it includes a pressure chamber that surrounds the device as taught by Fradet for the benefit of avoiding contamination when loading the solution inside a microfluidic device (Fradet; page 2 lines 28-29 and page 3 lines 1-4).
Response to Arguments
Applicant's arguments filed 09/26/2025 have been fully considered but they are not persuasive.
Applicant argues on page 3 of 4 of the remarks filed 09/26/2025 that Lee is unlike droplet-based approaches, and that Collins teaches thermocycling of single cell encapsulated droplets and that therefore one skilled in the art would not look to Collins. Examiner respectfully disagrees.
Examiner does agree that Lee describes a multilayer high density well array and recites “Moreover, unlike droplet-based approaches, this eliminates the need for surfactants.” (Lee; [0007], and see [0032]). Additionally, see [0006] of Lee which recites “however, droplets are prone to movement over time,”
It is understood that Collins is not directed to the same droplets that Lee is describing in [0006], [0007] and [0032]. Specifically, see [0024] of Collins that recites “PILLAR technology, first traps single cells at configured micropillars and then encapsulates using immiscible fluids around the single cell traps as picoliter reservoirs.” [0122] of Collins does describe the formation of a droplet, however the droplet is within a trapping site formed by micropillars, six micropillars as seen in Figure 25. Therefore, Collins is similar to Lee in the way that a sample of interest is captured in a physical structure and is then “encapsulated” by an immiscible fluid.
It is also noted that the sample within the wells of Lee can be considered “droplets” as there is a set amount of fluid within the well that is then sealed by oil.
Therefore, it is maintained that one skilled in the art would find it obvious to modify Lee with the manifold and software control of Collins, as both Lee and Collins are directed to trapping a sample within a physical structure that is then closed off by an immiscible fluid.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SOPHIA LYLE whose telephone number is (571)272-9856. The examiner can normally be reached 8:30-5:00 M-Th.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Elizabeth Robinson can be reached at (571) 272-7129. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/S.Y.L./Examiner, Art Unit 1796
/ELIZABETH A ROBINSON/Supervisory Patent Examiner, Art Unit 1796