JP2013102733A - Microorganism detecting device - Google Patents

Abstract

Provided is a microorganism detection apparatus that can easily measure microorganisms quickly even with a low-concentration sample solution.
A microorganism detection apparatus 1 for detecting microorganisms in a liquid. A concentration unit 12 that is arranged downstream of the receiving unit 11 that receives the sample solution, continuously concentrates the received sample solution, a pretreatment unit 13 that adds a reagent to the concentrated sample solution, and a detection unit that detects microorganisms 14. The concentration unit 12 includes a first microchannel 26 through which the sample solution flows and a second microchannel 27 through which gas flows in contact therewith. The depth of the first microchannel 26 is 100 μm or less. The sample liquid and the gas form a two-phase flow that overlaps. While the sample liquid flows through the first microchannel 26, the water in the sample liquid evaporates and moves to the gas side flowing through the second microchannel 27, whereby the sample liquid is concentrated.
[Selection] Figure 3

Description

  The present invention relates to a microorganism detection apparatus that detects microorganisms in a liquid.

  In order to prevent microbial contamination, water utilities that manage drinking water and drinking water manufacturers that produce commercial drinking water routinely conduct microbial tests on prescribed items stipulated in water quality standards. Has been done. For example, the number of general bacteria is required to be 100 / ml or less, and in order to confirm that the standard is satisfied, a microbiological test is performed to count general bacteria in the irrigation water.

  Usually, such a test uses a so-called culture method in which a sample solution sampled is added to a culture medium and cultured, and the number of colonies detected is counted. However, the culture method has a problem that it takes several days until a test result is obtained in addition to requiring specialized equipment and techniques. Therefore, a rapid measurement method has been proposed in which the inspection result can be known in a few hours. As an example, there are ATP method and fluorescence flow cytometry method, for example.

  The ATP method utilizes the property that a specific enzyme (luciferase) emits light depending on the amount of ATP (adenosine triphosphate) present in cells, and luciferase is converted into ATP extracted from bacteria in a sample solution. By reacting, microbial contamination can be investigated from the amount of luminescence. Usually, the ATP method is used for examining the presence or absence of microbial contamination with a large number of bacteria such as a wiping test, and is not used for counting bacteria.

  In contrast, fluorescent flow cytometry can count bacteria. Specifically, in the fluorescence flow cytometry method, bacteria in a sample solution are stained with a predetermined fluorescent dye, and then the sample solution is caused to flow through a microchannel through which the bacteria can flow one by one. The microchannel is irradiated with a laser having a predetermined wavelength, and the stained bacteria emit fluorescence by the laser light. By detecting the fluorescence, bacteria are detected and the number of bacteria is counted. A microorganism testing apparatus using such a fluorescent flow cytometry method is disclosed in Patent Document 1, for example.

  In relation to the present invention, a two-phase stabilization chip is disclosed in which a convex channel formed by combining two channels having different cross-sectional shapes is formed in a microchip (Patent Document 2). According to the flow path having the special shape, a stable two-phase flow can be formed, which suggests the use of the emulsion for phase separation and gas-liquid reaction.

JP 2008-157829 A Japanese Patent No. 4528585 JP 2008-221058 JP 2009-195156 A

  The ATP method and the fluorescence flow cytometry method can simplify the test, and the test results can be obtained in a few hours, and thus are expected as test methods that can replace the culture method.

  However, when the microbial concentration is very low as in the above-described aqueous microbiological test, these ATP methods and fluorescent flow cytometry methods require a process of concentrating the sample solution as a pretreatment.

  As a sample liquid concentration treatment method, for example, a method of capturing and recovering bacteria by filtering with a filter (Patent Document 3), or forming a layer of a large number of magnetic particles on the surface of the filter, A method of peeling bacteria together with magnetic particles after deposition (Patent Document 4) is known. However, both methods are time-consuming and time-consuming.

  Therefore, an object of the present invention is to provide a microorganism detection apparatus that can easily perform rapid microorganism measurement even with a low-concentration sample solution.

  The microorganism detection apparatus according to the present invention is a microorganism detection apparatus for detecting microorganisms in a liquid, and is arranged on the downstream side of the receiving part for receiving the sample liquid and the receiving part, and continuously concentrates the received sample liquid. A concentration unit, a pretreatment unit disposed downstream of the concentration unit and adding a reagent that acts on microorganisms to the concentrated sample solution; and disposed downstream of the pretreatment unit and adding the reagent. And a detection unit for detecting microorganisms from the sample solution.

  The concentrating unit includes a chip, a first microchannel formed in the chip and through which a sample solution flows, and a second microchannel through which gas flows in contact with the first microchannel. The depth of the first microchannel is formed to be 100 μm or less. The sample liquid flowing through the first microchannel and the gas flowing through the second microchannel form an overlapping two-phase flow. Then, while the sample liquid flows through the first microchannel, the sample liquid is concentrated by evaporating moisture in the sample liquid and moving to the gas side flowing through the second microchannel. It is configured.

  “Liquid” as used herein mainly means water, but may include other components such as commercially available soft drinks. Further, “evaporation” means that the moisture of the sample liquid is vaporized through the gas-liquid interface between the sample liquid flowing through the first microchannel and the gas flowing through the second microchannel.

  According to the microorganism detection apparatus configured as described above, the sample solution received in the receiving unit then flows into the micro first micro flow channel having a micro size having a depth of 100 μm or less. The first microchannel is in contact with the second microchannel through which the gas flows, and a two-phase flow in which the sample solution and the gas overlap is formed. While the sample liquid flows through the first microchannel, the water in the sample liquid evaporates and moves to the gas side flowing through the second microchannel.

  At this time, since the depth of the first microchannel is very small, the relative area of the gas-liquid interface with respect to the flow rate of the sample liquid can be greatly increased. Moreover, since the gas in contact with the sample liquid flows, the vapor pressure of the gas is always kept unsaturated, and the evaporation efficiency is not lowered. As a result, even in a normal temperature range where bacteria survive, concentration of 10 times or more is possible only by flowing the sample solution through the first microchannel.

  That is, according to this microorganism detection apparatus, the sample liquid evaporates at a constant rate while passing through the concentration section only by supplying a constant flow of gas and a small amount of sample liquid to the concentration section, and the sample continuously. The liquid can be concentrated. Accordingly, rapid inspection of microorganisms can be easily performed even with a low-concentration sample solution.

  Specifically, the width of the first microchannel is preferably 500 μm or less.

  By doing so, it is possible to stably form a two-phase flow in which the sample liquid and the gas overlap.

  For example, the first microchannel and the second microchannel may be configured to be partitioned by a porous partition film having a group of pores communicating with these channels.

  Then, a more stable two-phase flow can be formed without greatly hindering the evaporation of the sample liquid.

  In that case, it is preferable to make the pore diameter smaller than the microorganism to be detected.

  If it does so, it can prevent that microorganisms leak to the 2nd micro channel side through which gas flows, and can improve detection accuracy.

  Moreover, it is preferable that the concentrating part has a temperature adjusting mechanism capable of adjusting the temperature of the sample liquid flowing through the first microchannel.

  Since the amount of evaporation changes according to the temperature change, the temperature adjustment mechanism keeps the temperature of the sample liquid flowing through the first microchannel constant while compensating for the heat of vaporization, so that the degree of concentration remains constant regardless of the environmental temperature. Can be held. Therefore, since a stable concentration rate can be obtained, detection accuracy can be increased.

  According to the microorganism detection apparatus of the present invention, it is possible to continuously concentrate a sample solution by using a micro-size concentration unit. Can be done.

It is the schematic of a microorganisms detection apparatus. It is the schematic which shows the structure of a microorganisms detection apparatus. It is a schematic perspective view which shows a concentration part. It is a schematic plan view which shows a concentration part. For convenience, the flow path is represented by a solid line. It is a schematic sectional drawing in the II line | wire in FIG. In order to show the principal part inside a concentration part, it is the schematic represented by notching a part. (A)-(c) is the schematic which shows an example of the manufacturing process of a concentration part. It is the schematic which shows a pre-processing part and a detection part. It is a graph which shows the result of a verification test. It is the schematic which shows the modification of a concentration part. It is a schematic sectional drawing which shows the principal part of the concentration part of FIG. It is a schematic sectional drawing which expands and shows the principal part of FIG. It is the schematic which shows another modification of a concentration part. It is a schematic sectional drawing which shows the principal part of the concentration part of FIG. It is a schematic sectional drawing which expands and shows the principal part of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following description is merely illustrative in nature and does not limit the present invention, its application, or its use. In addition, in the description, for the sake of convenience, expressions representing directions such as up and down are used. However, since the influence of gravity is small in the micro device, these expressions do not limit the installation direction.

  In FIG. 1, the microorganisms detection apparatus 1 of this embodiment is shown. The microbe detection apparatus 1 is connected to, for example, water supply pipes 2 in tap water at drinking water facilities or drinking water manufacturing factories, and is used for microbiological tests such as the number of general bacteria and coliform bacteria defined in water quality standards. The microorganism detection apparatus 1 extracts a sample solution used as a specimen from the supply pipe 2 through the sampling pipe 3, inspects the microorganism, and then discharges the waste liquid through the drain pipe 4. The microorganism detection apparatus 1 is designed to automatically sample a sample solution and execute a microorganism test.

  FIG. 2 shows the configuration of the microorganism detection apparatus 1. The microorganism detection apparatus 1 includes a receiving unit 11, a concentration unit 12, a preprocessing unit 13, a detection unit 14, a counting unit 15, a control unit 16, and the like.

(Control part)
The control unit 16 includes hardware such as a CPU and a memory, and software such as a control program mounted on the hardware. The control unit 16 controls the overall operation of the microorganism detection apparatus 1 in cooperation with the receiving unit 11, the concentration unit 12, the preprocessing unit 13, the detection unit 14, and the counting unit 15.

(Reception Department)
The receiving unit 11 receives the sample solution through the sampling pipe 3. The receiving unit 11 receives a predetermined amount of sample liquid at predetermined timings that are continuous or intermittent, and supplies the received sample liquid to the subsequent concentration unit 12 at a constant flow rate.

(Concentration part)
The concentration unit 12 is disposed on the downstream side of the receiving unit 11 and has a function of continuously concentrating the received sample solution. The structure of the concentration part 12 is shown in FIGS.

  As shown in FIG. 3, the concentration unit 12 of the present embodiment includes a rectangular thin plate-shaped chip 21 with a small appearance. Incidentally, the chip 21 of this embodiment has a length dimension (L) of 15 mm, a width dimension (M) of 20 mm, and a thickness dimension (N) of 1.6 mm.

  As shown in FIGS. 5 and 6, the chip 21 is a laminated body of thin plates of a glass plate 22, a silicon plate 23, and a silicon nitride plate 24. A silicon plate 23 is disposed below the chip 21, and a glass plate 22 is disposed above the silicon plate 23 with a silicon nitride plate 24 interposed therebetween.

  A first microchannel 26 and a second microchannel 27 are formed inside the chip 21. The first microchannel 26 is a channel through which the sample solution flows, and the second microchannel 27 is a channel through which the dehydrated gas flows. The dehydrated gas is preferably dry. For example, dry nitrogen gas can be used as the dehydrated gas.

  The first microchannel 26 and the second microchannel 27 extend from one end to the other end in the length direction of the chip 21 while meandering in a wavy shape. Each of the first microchannel 26 and the second microchannel 27 has an action site 28 that overlaps with each other in the middle (the portion indicated by a thick line in FIGS. 3 and 4). The sample liquid and the dehydrated gas form a two-phase flow that overlaps vertically at the working site 28.

  As shown in FIGS. 5 and 6, the first microchannel 26 is a micro (μm) size bottom shallow groove formed on the upper surface of the silicon plate 23, and has a rectangular cross section having substantially the same width and depth. Have. The first microchannel 26 of the present embodiment is formed with a depth (h1) of about 8 μm and a width (w) of about 100 μm. The length of the first microchannel 26 is about 80 mm.

  The second microchannel 27 is a micro-sized groove formed on the lower surface of the glass plate 22 so as to face the first microchannel 26 in the vertical direction, and has substantially the same width and depth as the first microchannel 26. It has a rectangular cross section. The second microchannel 27 of the present embodiment is formed with a depth (h2) of about 40 μm and a width (w) of about 100 μm. The length of the second microchannel 27 is also formed to be about 80 mm.

  The depth of the first microchannel 26 is preferably set to at least 100 μm or less. If it exceeds 100 μm, the amount of the sample liquid flowing through the first microchannel 26 increases, and the area of the gas-liquid interface becomes relatively small, so that the evaporation efficiency decreases. Further, the channel width of the first microchannel 26 and the second microchannel 27 is preferably 500 μm or less. If it exceeds 500 μm, there is a possibility that a stable two-phase flow cannot be formed at the action site 28.

  As shown in FIGS. 3 and 4, the first micro flow channel 26 has a large-diameter liquid intake port 29 connected to the receiving unit 11 through a pipe t <b> 1 at the upstream end thereof, and the downstream end thereof. The part has a large-diameter liquid outlet 30 connected to the pretreatment part 13 through the pipe t2. The liquid inlet 29 and the liquid outlet 30 are open on the lower surface of the silicon plate 23.

  On the other hand, the second microchannel 27 has a large-diameter air supply port 31 connected to the dehydrating gas supply source S through the pipe t3 at the upstream end thereof, and the pipe t4 at the downstream end thereof. And a large-diameter exhaust port 32 connected to a gas exhaust port (not shown). The air supply port 31 and the exhaust port 32 are also opened on the lower surface of the silicon plate 23.

  The liquid intake port 29 and the air supply port 31 are located apart from each other in the width direction at one end in the length direction of the chip 21 so that the pipe can be easily connected. The liquid intake port 29 and the liquid discharge port 30 are diagonally positioned with respect to the chip 21, and the air supply port 31 and the exhaust port 32 are also positioned diagonally with respect to the chip 21. . Accordingly, the liquid discharge port 30 and the exhaust port 32 are also located apart from each other in the width direction at the other end in the length direction of the chip 21.

  As shown in FIGS. 5 and 6, in the action site 28, the first microchannel 26 and the second microchannel 27 are partitioned by a porous partition plate 34. That is, the silicon nitride plate 24 is formed with a group of pores 34 a communicating with the first microchannel 26 and the second microchannel 27 along the action site 28, thereby forming the partition plate 34. Has been. The thickness of the silicon nitride plate 24 is nano (nm) size, and in this embodiment, the thickness is about 300 nm. For the sake of convenience, the thickness of the illustrated silicon nitride plate 24 is shown large.

  The pore diameter of the pore 34a is preferably smaller than that of the microorganism to be detected (because it is mainly bacteria, hereinafter also referred to as bacteria). By doing so, it is possible to prevent bacteria in the sample solution from leaking to the second microchannel 27 side, so that the detection accuracy can be increased. However, since the partition plate 34 stabilizes the two-phase flow of the sample liquid and the dehydrated gas and does not filter the sample liquid, the pore diameter may be larger than that of the bacteria. Therefore, the pore diameter of the pore 34a of the present embodiment is set to a size of 1 μm or more through which bacteria can pass.

  Since the direction in which the pores 34a extend is substantially orthogonal to the direction in which the bacteria flow, even if the bacteria are smaller than the pores 34a, the leakage of bacteria is effectively suppressed. In addition, it is preferable that the partition plate 34 provides water repellency. By doing so, it is possible to reliably prevent the sample solution and bacteria from leaking out to the second microchannel 27 side without hindering the evaporation of moisture in the sample solution.

  As shown in FIG. 7, the chip 21 having such a configuration is manufactured by using a manufacturing technique such as a semiconductor. Specifically, as shown in FIG. 3A, a silicon nitride plate 24 is formed on the surface of the silicon plate 23, and the surface is further covered with a resist film 41. Then, as shown in FIG. 4B, a part of the pores 34a, the liquid intake port 29, the liquid discharge port 30, and the like are formed in the silicon nitride plate 24 by using a photolithography technique. Thereafter, as shown in FIG. 3C, the remaining portions such as the first micro flow path 26 and the liquid discharge port 30 are formed in the silicon plate 23 by using an etching technique. Thereafter, the resist film 41 may be removed and bonded to the glass plate 22 on which the second microchannel 27 is formed. Incidentally, the second microchannel 27 is formed by performing photolithography and hydrofluoric acid etching on the glass plate 22.

  As shown in FIG. 4, a sheet-like heater 43 capable of adjusting the temperature is attached to the chip 21 on the first micro flow path 26 side (an example of a temperature adjusting mechanism). The sample liquid flowing through the first microchannel 26 is held constant by the heater 43 at a preset temperature. In addition, since it is common to target living bacteria in the microbiological examination, the sample solution is not usually heated to a temperature at which the bacteria die. Therefore, the temperature of the sample solution is maintained within the range of the bacterial survival temperature (at least 50 ° C. or less).

  Next, processing of the sample solution in the concentration unit 12 will be described.

  As shown by arrows in FIGS. 3 and 4, the sample liquid sent from the receiving unit 11 at a constant flow rate flows into the first microchannel 26 from the liquid intake port 29. At least at that time, the dehydrated gas flows through the air supply port 31 to the second microchannel 27 at a constant flow rate.

  When the sample liquid flowing through the first microchannel 26 reaches the action site 28, it contacts the dehydrated gas flowing through the second microchannel 27 on the upper side via the partition plate 34, thereby forming a gas-liquid two-phase flow. Is done. Therefore, at the action site 28, the sample liquid always comes into contact with the dehydrated gas dried with a relatively large surface area, so that the water in the sample liquid evaporates, and as shown by the broken line in FIG. The water vapor moves to the dehydrated gas side through the pores 34a.

  Since the dried dehydrated gas is always supplied to the second microchannel 27 at a constant flow rate, the vapor pressure of the dehydrated gas is maintained in an unsaturated state, high evaporation efficiency can be ensured, and the sample liquid Even if it is continuously flowed, the evaporation efficiency is kept constant and stable concentration can be performed.

  Since the sample liquid flowing through the first microchannel 26 is also supplied at a constant flow rate and maintained at a constant temperature, it can always be concentrated at a constant concentration rate even if it is continuously processed.

  Since the sample liquid and the dehydrated gas flow in the same direction, a stable two-phase flow can be formed. In addition, since the dehydrated gas in the most dry state comes into contact with the sample solution first, the moisture in the sample solution can be efficiently evaporated.

(Pre-processing section)
The pretreatment unit 13 is disposed on the downstream side of the concentration unit 12 and has a function of adding a reagent that acts on bacteria to the concentrated sample solution. The microorganism detection apparatus 1 of the present embodiment is configured to detect viable bacteria based on the ATP method and to count the number thereof, and the preprocessing unit 13 performs the preprocessing.

  FIG. 8 shows the configuration of the preprocessing unit 13. The pretreatment unit 13 includes a first injection path 52, a second injection path 53, an oil liquid injection path 54, and the like connected to a fine main channel 51 through which the concentrated sample solution flows.

  The main flow path 51 is configured with a flow path having a minute inner diameter so that bacteria can flow one by one.

  The first injection path 52 injects a lysis reagent into the main channel 51 from a supply destination outside the figure, and the second injection path 53 injects a luminescent reagent into the main channel 51 from a supply destination outside the figure. If bacteria exist in the sample solution, the lysis reagent dissolves the cell membrane and elutes ATP present in the bacteria. A luminescent reagent contains the enzyme (luciferase) which reacts with ATP and emits fluorescence. The second injection path 53 is arranged before and after the first injection path 52. If the lysis reagent and the luminescent reagent are mixed into one, either the first injection path 52 or the second injection path 53 can be omitted.

  The oil liquid injection path 54 is disposed on the downstream side of the first injection path 52 and the second injection path 53, and the oil liquid in the main flow path 51 is formed so that a droplet of the sample liquid is formed from a supply destination outside the figure. Inject liquid. The lysing reagent, the luminescent reagent, and the oil solution are respectively injected in predetermined amounts in conjunction with the flow of the sample solution flowing through the main channel 51.

  In the pretreatment unit 13 of the present embodiment, first, a lysis reagent is injected into the concentrated sample solution. When bacteria are present in the sample solution, the bacteria are dissolved by the lysis reagent, and ATP is eluted in the sample solution. Around that time, a luminescent reagent is injected into the sample solution. If ATP is present in the sample solution, the luminescent reagent reacts with ATP to generate fluorescence.

  Thereafter, the sample liquid is divided into a predetermined amount of droplets by injection of the oil liquid. When bacteria are present in the sample solution, the size and the like of the droplets are set so that one droplet contains ATP extracted from approximately one bacterium.

(Detection unit, counting unit)
As shown in FIG. 8, the detection unit 14 is arranged on the downstream side of the pretreatment unit 13 and has a function of optically detecting bacteria from the sample solution to which the reagent is added. The detection unit 14 of the present embodiment includes a detector 61 that detects fluorescence generated by the reaction between ATP and a luminescent reagent. The detector 61 is installed in the vicinity of the main channel 51 through which the droplets flow. The detector 61 outputs a detection signal to the counting unit 15 when detecting a droplet emitting fluorescence. The counting unit 15 counts the number of bacteria based on the detection signal input from the detecting unit 14 and outputs the result through a display unit or the like not shown.

  The sample liquid that has passed through the detection unit 14 is discharged as waste liquid through the drainage pipe 4.

(Verification test)
In order to verify the performance of the concentrating part, a verification test was conducted to examine the effects of the temperature of the sample solution and the flow rate of the dehydrated gas on the evaporation amount. In the test, the concentration unit 12 shown in the above-described embodiment was used alone. Dry nitrogen gas was used as the dehydration gas, and water (pure water) was used as the sample solution.

  In the test, since it was difficult to directly measure the evaporation amount, the liquid discharge port 30 was forcibly sealed, and the second microchannel 27 was supplied with 0.2 to 0.6 MPa of dry nitrogen gas at a predetermined flow rate. The water was injected into the first microchannel 26 from the liquid intake port 29 while flowing into the first microchannel 26. Then, it was observed that water leaked from the exhaust port 32, and the maximum evaporation amount was estimated at the time when water leaked.

  FIG. 9 shows the test results. The vertical axis represents the maximum evaporation amount, and the horizontal axis represents the flow rate of dry nitrogen gas. As shown in the figure, there was no proportional relationship between the gas flow rate and the maximum evaporation at a temperature of 50 ° C, but a proportional relationship was observed at 40 ° C and 27 ° C, which increased the gas flow rate. Along with this, the amount of evaporation also increased at a constant rate. Further, it was confirmed that the concentration rate could be concentrated 10 times or more.

  Therefore, it is possible to concentrate the sample solution continuously and stably by adjusting the flow rate of the sample solution and gas and the temperature of the sample solution, and the concentration rate can be controlled by adjusting the gas flow rate. It was confirmed.

(Modification)
For example, in the above-described embodiment, the example in which the first micro flow path 26 and the second micro flow path 27 in the action site 28 are partitioned by the partition plate 34 has been described. And dehydrated gas may be in direct contact.

  10 to 12 show specific examples. FIG. 10 shows the concentrating unit 12 in which the glass plate 22 and the silicon plate 23 are shown separately. For convenience, the same components as those in the previous embodiment are denoted by the same reference numerals and description thereof is omitted.

  In this modified example, the form of the first microchannel 26 and the second microchannel 27 at the action site 28 is devised so that the interface of the dehydrated gas can be stably maintained even if the partition plate 34 is omitted. . That is, the first micro flow path 26 is branched into a plurality of (eight in the present modification) first element flow paths 26 a at the action site 28. The second micro flow path 27 also branches into a plurality of (eight in the present modification) second element flow paths 27 a corresponding to the first element flow paths 26 a at the action site 28. The second element channel 27a is subdivided (divided into 16 equal parts) and further branched into a plurality of subdivided channels 27b.

  As a result, as shown in FIG. 11, in the action site 28, the 16 subdivided channels 27b are vertically overlapped with the one first microelement channel 26a.

  FIG. 12 shows an enlarged schematic cross-sectional view of each segmented flow path 27b. A liquid repellent layer 28 a having liquid repellency is formed on the surface of the glass plate 22 at the action site 28 by applying a hydrophobic treatment. The liquid repellent layer 28a is also formed on the side wall surface of the subdivided flow path 27b.

  As shown in FIG. 10, a hydraulic pressure adjusting device 80 that adjusts the hydraulic pressure is installed downstream of the liquid discharge port 30, and an atmospheric pressure adjusting device 81 that adjusts the atmospheric pressure is installed downstream of the exhaust port 32. is set up. The balance between the liquid pressure of the sample liquid flowing through the action site 28 and the atmospheric pressure of the dehydrated gas is adjusted by the liquid pressure adjusting device 80 and the atmospheric pressure adjusting device 81.

  By doing so, as shown in FIG. 12, even without the partition plate 34, for example, a part of the sample liquid can be held in a state where it swells inside the subdivided flow path 27 b due to surface tension, The gas-liquid interface can be stably maintained.

  As shown in FIG. 13, the configurations of the first microchannel 26 and the second microchannel 27 may be reversed.

  Specifically, the first micro flow channel 26 and the second micro flow channel 27 are divided into a plurality of (eight in this modification) first element flow channel 26a and second element flow channel 27a at the action site 28. Branched. The first element channel 26a is subdivided (divided into 16 equal parts) and further branched into a plurality of subdivided channels 26b.

  As a result, as shown in FIG. 14, in the action site 28, the 16 subdivided channels 26b are vertically overlapped with the one second microelement channel 27a.

  FIG. 15 is a schematic cross-sectional view showing an enlarged portion of each subdivided flow channel 26b. In this case, a liquid repellent layer 28 a having liquid repellency is formed on the surface of the action site 28 of the glass plate 22 by performing a hydrophobic treatment. A hydrophilic layer 28b having hydrophilicity is formed on the side wall surface of the subdivided flow path 27b by applying a hydrophilic treatment.

  By doing so, as shown in FIG. 15, even without the partition plate 34, for example, a part of the sample liquid can be held in a state in which it swells inside the second element channel 27 a due to surface tension. The gas-liquid interface can be stably maintained.

  In addition, the microorganisms detection apparatus concerning this invention is not limited to embodiment mentioned above, The other various structure is included.

  For example, in the embodiment described above, an example in which the number of viable bacteria is counted using the ATP method in the preprocessing unit 13 and the detection unit 14 is shown, but the present invention is not limited thereto, and the fluorescent flow cytometry method may be used. Good. The detection of microorganisms is not limited to these optical methods. For example, other physical and chemical detection methods such as an electrical method and a magnetic method may be used.

  In addition, a plurality of chips 21 can be connected or enlarged, and the form of the first microchannel 26 and the second microchannel 27 can be appropriately changed according to the specifications. For example, the air supply port 31, the exhaust port 32, the liquid intake port 29, and the liquid discharge port 30 may be formed on any one of the glass plate 22 and the silicon plate 23, or the first micro flow channel 26 and the second The micro flow path 27 may also be formed on either the glass plate 22 or the silicon plate 23.

  The microorganism detection apparatus of the present invention can be used, for example, for water quality management of waterworks or water quality management of water in the food industry.

DESCRIPTION OF SYMBOLS 1 Microbe detection apparatus 11 Reception part 12 Concentration part 13 Pretreatment part 14 Detection part 15 Count part 16 Control part 21 Chip 26 1st micro flow path 27 2nd micro flow path 28 Action part 34 Partition plate 34a Pore 43 Heater (temperature) Adjustment mechanism)

Claims (5)

A microorganism detecting apparatus for detecting microorganisms in a liquid,
A receiving part for receiving the sample liquid;
A concentration unit that is arranged downstream of the receiving unit and continuously concentrates the received sample liquid;
A pretreatment unit that is disposed downstream of the concentration unit and adds a reagent that acts on microorganisms to the concentrated sample solution;
A detection unit that is arranged on the downstream side of the pretreatment unit and detects microorganisms from the sample solution to which the reagent is added;
With
The concentration unit includes
Chips,
A first microchannel formed in the chip and through which a sample solution flows;
A second microchannel through which gas flows in contact with the first microchannel;
Have
The first microchannel has a depth of 100 μm or less,
The sample liquid flowing through the first microchannel and the gas flowing through the second microchannel form an overlapping two-phase flow,
While the sample liquid is flowing through the first microchannel, the microorganism detection apparatus in which the sample liquid is concentrated by evaporating moisture in the sample liquid and moving to the gas side flowing through the second microchannel . The microorganism detection apparatus according to claim 1,
A microorganism detecting apparatus, wherein the width of the first microchannel is 500 μm or less. In the microorganism detection device according to claim 1 or 2,
A microorganism detecting apparatus in which the first microchannel and the second microchannel are partitioned by a porous partition plate having a group of pores communicating with these channels. The microorganism detection apparatus according to claim 3,
A microbe detection apparatus in which the pore diameter is smaller than the target microbe. In the microorganism detection apparatus according to any one of claims 1 to 4,
The microorganism detecting apparatus, wherein the concentrating unit has a temperature adjusting mechanism capable of adjusting the temperature of the sample solution flowing through the first microchannel.

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