JP4640104B2 - Microorganism measuring apparatus and microorganism measuring method - Google Patents

Description

  The present invention relates to a microorganism collection and measurement tool, and more particularly to a microorganism collection and measurement tool for collecting and measuring microorganisms attached to various surfaces.

Conventionally, as a technique for collecting microorganisms that live on the surface of living tissues such as skin and mucous membranes, and surfaces such as kitchens, baths, floors, walls, etc., there is a technique that collects them by generating a quantitative movement on the surface of collecting microorganisms. It has been proposed (Patent Document 1).
JP 2003-334059 A

  However, the conventional collection tool only collects microorganisms, and it is necessary to use other means for examining the collected microorganisms. In addition, microbiological examinations need to be performed hygienically, from collection of measurement samples to examinations, and disposal of samples and materials that may be contaminated with samples, but the technology for performing the series of operations is described. Not.

  In addition, microbiological tests require not only microorganisms present on the surface, but also microorganisms present in a suspended state in liquids such as tap water, water in storage tanks, and drinking water. No technical proposal has been made regarding an apparatus capable of testing microorganisms in a liquid.

  The present invention has been made in view of the above-described conventional circumstances, and it is possible to sanitarily perform sampling of a microorganism measurement sample, measurement of the number of microorganisms, disposal of the sample and materials possibly contaminated with microorganisms on the spot. An object of the present invention is to provide a microorganism measuring apparatus and a microorganism measuring method that can be performed quickly.

The microorganism measuring apparatus of the present invention is a microorganism measuring apparatus for collecting and measuring microorganisms, and can hold a liquid and a head portion having a microorganism collecting surface and a dielectrophoresis electrode on the same substrate. A measurement cell detachable from the head unit, a dielectrophoresis electrode, and a measurement main body are provided.

According to the above configuration, it is possible to quickly collect and measure microorganisms on the surface with a single device, and even using a general container such as a beaker without a dedicated measurement cell. Microorganism testing can be performed, and furthermore, a measurement sample in a state in which microorganisms are suspended in a liquid can be directly measured, and the versatility of the microorganism measuring apparatus is increased.
The

  The microorganism measuring apparatus of the present invention is a microorganism measuring apparatus for collecting and measuring microorganisms, comprising a microorganism collecting surface, a head portion having a dielectrophoretic electrode formed on the microorganism collecting surface, and a liquid. A measurement cell detachably attached to the head part that can be held, and a measurement main body.

  According to the above configuration, since the microorganism collecting surface also serves as the substrate of the dielectrophoresis electrode, the manufacturing process and material costs can be reduced.

  In the microorganism measuring apparatus of the present invention, the head part and the measuring body are detachably connected.

  According to the said structure, the head part which may be contaminated with microorganisms can be disinfected hygienically.

  In the microorganism measuring apparatus of the present invention, the microorganism collecting surface is made of a filter material having an effective diameter of 0.05 to 5 μm.

  According to the said structure, a microorganism can be reliably hold | maintained by using the filter of the hole diameter comparable as the dimension of the microorganisms of collection | acquisition object on the surface of a microorganisms collection surface.

  Further, in the microorganism measuring apparatus of the present invention, the measurement main body includes a vibration means, and applies linear reciprocation and / or rotational vibration to the head portion.

  According to the said structure, the microorganisms adhering to a to-be-collected surface can be peeled, and it can extract | collect reliably, and the precision of a microorganism test improves. In addition, since the relative position between the dielectrophoresis electrode and the liquid can be changed, more microorganisms can be supplied in the vicinity of the gap where the dielectrophoretic force acts, and the measurement sensitivity is improved.

Further, the microorganism measuring method of the present invention is a method of measuring microorganisms using the microorganism measuring apparatus of the present invention , wherein the microorganism collecting surface is brought into contact with the surface of the microorganism inspection target, and the microorganism is attached to the microorganism collecting surface. A microorganism collecting step, a step of impregnating a measurement cell containing liquid with a head portion and suspending microorganisms adhering to the microorganism collecting surface in the liquid, applying an alternating voltage to the dielectrophoresis electrode, Collecting the microorganism suspended in the measurement cell by the dielectrophoresis electrode and simultaneously measuring the impedance change, displaying the concentration of the microorganism in the measurement cell from the measured impedance change, And discarding the contaminated head without touching the contaminated portion.

The microorganism measuring method of the present invention is a method for measuring microorganisms using the microorganism measuring apparatus of the present invention, wherein the vibrating means provided in the measuring body at least simultaneously with the microorganism collecting step or the impedance measuring step Gives vibration to the head.

  According to the present invention, a microorganism measuring apparatus capable of hygienically and promptly performing sampling of a microorganism measurement sample, measurement of the number of microorganisms, disposal of a sample and a material possibly contaminated with microorganisms on the spot, and A method for measuring microorganisms can be provided.

(Embodiment 1)
Embodiment 1 of a microorganism collection tool of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic front view of a microorganism collection tool, and FIG. 2 is a schematic cross-sectional view showing a measurement cell for measuring microorganisms.

  In FIG. 1, the microorganism measuring apparatus 1 according to the first embodiment has a so-called toothbrush pattern-like form, and the head portion 2 and the measuring body 3 are made of any material such as plastic. The tip surface of the head portion 2 is electrically connected to the sampling surface 4 for attaching microorganisms on the surface of the microorganism collection target (hereinafter referred to as the surface to be collected), a dielectrophoresis electrode 12 (described in FIG. 3) and a measurement circuit to be described later. A plurality of head-side terminals 5 connected to the. The head unit 2 is connected to the measurement main body 3 in a detachable configuration.

  The sampling surface 4 is not particularly limited as long as it is a porous material. Various materials such as plastic materials such as PET, metal materials such as aluminum, fiber materials, and filter materials can be used. In this embodiment, a fluororesin membrane filter having a filter hole diameter of 0.5 μm is used. Yes. It is desirable that the filter hole diameter is approximately the same as the representative dimension of the microorganism to be measured. In order to capture from virus to yeast and protozoa, a hole diameter of 0.05 μm to 5 μm was selected here. As a result, the microorganisms on the surface to be collected can be reliably held in the filter, so that the microorganisms can be reliably collected from the surface to be collected, and a highly accurate microorganism test can be performed.

  The measurement main body 3 includes a display means 6 using an LCD or the like for displaying various information such as measurement results to an inspector and at least one operation switch 7. Furthermore, a buzzer using a piezoelectric element or various speakers (not shown) may be provided so that various statuses can be notified to the inspector.

  FIG. 2 is a schematic cross-sectional view of a measurement cell 8 for measuring microorganisms. In the measurement cell 8, a seal 10 is attached to an opening of a cell structure 9 for forming the liquid holding region 11. The liquid holding region 11 only needs to have a capacity necessary for measuring microorganisms, and is 5 ml in the present embodiment.

  The cell structure 9 is made of an arbitrary material that can hold a liquid and has a size that can secure the capacity. The seal 10 is formed of vinyl, PET, or a material in which an aluminum thin film is bonded to prevent the liquid retained inside the cell structure 9 from leaking to the outside. Any kind of liquid can be used as long as the microorganism to be measured is not destroyed by the osmotic pressure imbalance when the microorganism is suspended. Uses a mannitol solution which is a sugar alcohol.

  Further, the cell structure 9 is formed in a structure in which the opening can cover the sampling surface 4 of the head portion 2 in a state where the seal 10 is removed. Specifically, it is realized by, for example, threading around the sampling surface 4 of the head 2 and the opening inside the measurement cell 8.

  FIG. 3 is a schematic view seen from the opening side with the seal 10 (FIG. 2) of the measurement cell 8 removed. A dielectrophoretic electrode 12 formed of a metal thin film is provided on the bottom surface. The dielectrophoresis electrode 12 may be directly formed on the cell structure 9, but may be separately formed on a substrate such as glass or PET film and attached to the bottom surface of the cell structure 9. A cell-side terminal 13 that can be electrically connected to the head-side terminal 5 provided in the head unit 2 is provided on the end face of the opening of the measurement cell 8.

  FIG. 4 is an enlarged view of the dielectrophoretic electrode, which includes a plurality of poles 14 and 15, with a gap 16 formed between each pole. When an alternating electric field is applied between the dielectrophoretic electrodes 12, the microorganisms suspended in the liquid in the liquid holding region migrate toward the gap 16 where the electric field is concentrated most. For a more detailed description of dielectrophoresis, see “AC Electrokinetics: Colloids and Nanomolecules (Co-authored by Hewell Morgan and Nicholas G Green) (Research Studios Press LTD., 2002). (See Green)).

  For pattern formation of the dielectrophoretic electrode 12, a general method capable of forming a metal thin film pattern, such as photolithography, plating growth, and screen printing, can be applied. In the present embodiment, a pattern formed by screen printing on a PET film is used.

  FIG. 5 is a block diagram showing the connection between the dielectrophoresis electrode and the measurement circuit in the measurement main body when the measurement cell is attached to the head portion.

  The plurality of electrodes of the dielectrophoretic electrode 12 formed on the measurement cell 8 (FIG. 2) are electrically connected to each other by lead wires or the like in the head portion 2 (FIG. 1) via the main body side terminal 5 and the cell side terminal 13. And connected to the measurement unit 17 in the measurement main body 3 (FIG. 1). The measurement unit 17 supplies an AC voltage for generating dielectrophoresis to the dielectrophoresis electrode 12 and measures the current flowing through the electrode at this time.

  The calculation unit 18 calculates the impedance from the values of the AC voltage and the measurement current applied by the measurement unit 17. The control unit 19 includes a circuit including a CPU and a memory (not shown). The control unit 19 controls the measurement unit 17 for measurement operation, acquires data from the calculation unit 18, outputs data to the display unit 6, and operates from the operation switch 7. All control necessary for microbial measurement, such as input.

  Vibrating means 20 that applies rotational vibration, vertical vibration, vertical / horizontal vibration, or a combination of one or more of them to the head section 2 (FIG. 1) including the sampling surface 4 (FIG. 1) is provided to the control section 19. It is connected. The mechanism used as the vibration means 20 can be applied as long as the head unit 2 (FIG. 1) can be given the above-described vibration motion. In the present embodiment, a DC motor in which an eccentric weight is attached to the rotating shaft. Is used. The vibration means 20 is preferably installed in a portion closest to the head portion 2 (FIG. 1) inside the measurement main body 3 in order to efficiently transmit vibration to the head portion 2 (FIG. 1).

  The series of the measurement unit 17, the calculation unit 18, the control unit 19, and the vibration unit 20 are stored by forming a circuit in the measurement main body 3 using a PCB (Printed Circuit Board) substrate, a lead wire, or the like.

  Hereinafter, a series of flow (microorganism measurement method) from collecting a microorganism from the surface to be collected, displaying the microorganism, measuring and displaying the result, and discarding the contaminated portion will be described with reference to FIGS.

  First, a step of collecting microorganisms on the surface to be collected (hereinafter referred to as a collection step) will be described. The inspector holds the measurement body 3 in his hand and presses the sampling surface 4 against the surface to be sampled. Next, the tester presses the operation switch 7 to start collecting microorganisms. When the operation switch 7 is pressed in the initial state, the control unit 19 operates the vibration means 20 to apply a certain vibration to the sampling surface 4.

  Many microorganisms adhere to the surface to be collected by sticky polysaccharides such as glucan produced by themselves, cilia-like structures on the surface of the microorganisms, and other physicochemical adsorption. By simply pressing the surface, the number of microorganisms that can be held on the collection surface 4 is limited, and therefore the state of the microorganisms on the surface to be collected cannot be accurately inspected. Therefore, by applying vibration to the sampling surface 4 as in the present embodiment, microorganisms attached to the surface to be sampled can be peeled off and reliably sampled.

  When a certain period of time has elapsed since the vibration was started, the control unit 19 stops the operation of the vibration means 20, and preferably notifies the tester that the collection of microorganisms has been completed, for example, by sounding a buzzer. By making the time for applying vibration constant in this way, it is possible to maintain the quantitativeness of the microorganism test. The tester who recognizes that the collection of microorganisms has been completed separates the collection surface 4 from the surface to be collected, thereby completing the collection step.

  Next, a step of measuring the microorganisms collected on the collection surface 4 in the collection step (hereinafter referred to as measurement step) will be described.

  First, the inspection operator peels off the seal 10 attached to the measurement cell 8 and attaches the opening of the measurement cell 8 so as to match the sampling surface 4. At this time, the head side terminal 5 and the cell side terminal 13 are electrically connected.

  Next, the examiner presses the operation switch 7 to start measuring the number of microorganisms. When the operation switch 7 is pressed in a state where the sampling step is completed, the vibration unit 20 operates and at the same time, the measurement unit 17 starts applying an AC voltage to the dielectrophoresis electrode 12. By applying vibration to the measurement cell 8 at the time of measurement, microorganisms attached to the sampling surface 4 are easily suspended in the liquid and the relative position between the dielectrophoresis electrode 12 and the liquid is changed. Therefore, more microorganisms can be supplied to the vicinity of the gap 16 where the dielectrophoretic force acts, and the measurement sensitivity is improved.

  The microorganisms suspended in the liquid are concentrated toward the gap 16 by the dielectrophoretic force. When a sufficient number of microorganisms are trapped in the gap 16, the gap 16 is cross-linked by the microorganisms. Under the condition that the applied voltage and the applied vibration are constant, the number of microorganisms gathered in a predetermined region near the gap 16 after a predetermined time is proportional to the number of microorganisms in the liquid. The number of microorganisms can be calculated.

  In general, a microorganism can be equivalently expressed as an element in which resistance and capacitance are electrically connected in parallel. This is because microorganisms are ion-rich and surrounded by a cell wall having a relatively high electrical conductivity and a cell membrane made of phospholipid and having a low electrical conductivity. As the gap 16 is bridged by microorganisms that move to the gap 16 due to dielectrophoresis, the impedance (resistance component and capacitance component) of the dielectrophoresis electrode 12 changes. Since the number of microorganisms migrating to the gap 16 increases and the number of cross-links by microorganisms increases, the impedance changes in proportion to the number, so the value is present in the liquid in the vicinity of the gap 16 and thus in the liquid. A measurement result correlated with the number of microorganisms to be obtained can be obtained.

  Immediately after the application of an alternating voltage to the dielectrophoresis electrode 12 is started, the measurement unit 17 starts measuring the current flowing through the dielectrophoresis electrode 12. For the current measurement, a known technique such as voltage conversion via a shunt resistor can be used. The calculation unit 18 receives the current value measured by the measurement unit 17 and calculates an impedance value from the amplitude and frequency of the applied voltage and the phase difference between the current and voltage. The calculated impedance value is transferred to the control unit 19 and stored in a memory (not shown). A series of these operations are performed at regular time intervals, and as a result, changes in impedance when an AC voltage is applied to the dielectrophoretic electrode 12 are stored in the memory.

  When a predetermined time elapses, the control unit 19 stops the application of the alternating voltage, and calculates the number of microorganisms in the liquid from the stored impedance change. Since the concentration and measurement are performed electrically, the measurement can be performed in a very short time of about several minutes, and the measurement on the spot where microorganisms are collected can be realized.

  In order to correlate the impedance change and the number of microorganisms, a conversion formula between the impedance change and the number of microorganisms is necessary. This conversion equation is used to measure a sample solution for calibration with a clear number of microorganisms, store changes in impedance values when measured for a certain period of time as a table on a memory, and measure a sample with an unknown number of microorganisms. In this case, the measured impedance change is compared with the table to calculate the number of microorganisms.

  When the calculation of the number of microorganisms is completed, the control unit 18 displays the result on the display means, and preferably notifies the tester that the measurement step has been completed by sounding a buzzer. As a result display method, a numerical expression of the number of microorganisms may be used, or a stepwise level display may be performed.

  When the measurement step is completed, the tester confirms the measurement result, and then disconnects the head unit 2 from the measurement main body 3 and discards the head unit 2. There is a high possibility that the inside of the collection surface 4 and the measuring cell 8 is contaminated with microorganisms, and if touched here, there is a possibility of infection by microorganisms. In the present embodiment, since the entire head unit 2 can be discarded without touching the inside of the collection surface 4 and the measurement cell 8, it is possible to perform a microbial test hygienically.

  As described above, according to the first embodiment, it is possible to quickly collect and test microorganisms on the spot with a single device.

  In addition, the head portion that may be contaminated by microorganisms can be sanitized and the sanitary microorganism test can be performed for the tester.

  Moreover, microorganisms can be reliably held by using a filter having a pore size similar to the size of the microorganisms to be collected.

  Moreover, the microorganisms adhering to the surface to be collected can be peeled off by the vibration of the head portion 2 and can be reliably collected, and a highly accurate bacteria test can be performed. Further, since the relative position can be changed between the dielectrophoretic electrode 12 and the liquid in the measurement step, more microorganisms can be supplied to the vicinity of the gap 16 where the dielectrophoretic force acts, and the measurement sensitivity can be improved. improves.

(Embodiment 2)
Next, a second embodiment of the present invention will be described in detail with reference to the drawings. In the second embodiment, description overlapping with that of the first embodiment is omitted.

  FIG. 6 is a diagram showing a schematic front view and a cross section of the head portion in the second embodiment. The dielectrophoresis electrode 12 is formed on a substrate using an insulating material such as PET or polyimide. Further, the sampling surface 3 is bonded on the same substrate so as not to cover the gap 16 of the dielectrophoretic electrode 12. The lead wire from the dielectrophoretic electrode 12 is electrically connected to the measurement unit 17 of the measurement body 3 by providing wiring means such as a lead wire (not shown) in the head unit 2.

  FIG. 7 is a diagram showing another embodiment of the head portion and the cross section of the head portion in the second embodiment. As shown in FIG. 7, the dielectrophoretic electrode 12 can be directly formed on the collection surface 3. Since the substrate on which the dielectrophoretic electrode 12 is formed and the sampling surface 3 can be made common, there are merits that materials and manufacturing processes can be reduced, and the cost of the apparatus can be reduced.

  Hereinafter, in the second embodiment, a series of steps from collecting a microorganism from a surface to be collected, measuring and displaying the microorganism, and discarding the contaminated part will be described. The steps up to the collecting step are the same as those in the first embodiment. Since it is similar, only the measurement step will be described.

  First, the tester peels off the seal 10 attached to the measurement cell 8 and attaches it so that the opening of the measurement cell 8 covers the sampling surface 4. The measurement cell 8 used in the second embodiment does not need to include the dielectrophoresis electrode 12 and the cell side terminal 13.

  Further, according to the microorganism measuring apparatus of the second embodiment, it is not always necessary to use the dedicated measuring cell 8, and the head unit 2 is impregnated in a general container holding a liquid used for measurement such as a beaker. It is also possible to measure, and the versatility of the measurement is increased.

  Next, the examiner presses the operation switch 7 to start measuring the number of microorganisms. Since the following operation is the same as that of Embodiment 1, description is abbreviate | omitted.

  As described above, according to the second embodiment, it is possible to perform a microbial test using a general container such as a beaker without a measurement cell, and to provide a highly versatile microbial measurement apparatus.

(Embodiment 3)
Next, a third embodiment of the present invention will be described. In the third embodiment, the description overlapping that of the first and second embodiments is omitted.

  In the third embodiment, the apparatus used in the second embodiment, in which the dielectrophoretic electrode 12 for microbial measurement is provided on the head unit 2, is used. In the third embodiment, not the microorganisms present on the surface to be collected, but the microorganisms already suspended in water, such as tap water, water in a storage tank, and drinking water, are to be measured.

  The inspector first impregnates the tip of the head unit 2 and the dielectrophoresis electrode 12 in the liquid to be inspected. Next, when the operation switch 7 is pressed, measurement of the number of microorganisms is started. Since the following operations are the same as those in the first and second embodiments, description thereof will be omitted.

  As described above, according to the third embodiment, not only the microorganisms on the surface to be collected but also the measurement sample in a state where the microorganisms are suspended in the liquid can be directly measured. Becomes higher.

(Embodiment 4)
The number of microorganisms was measured using the microorganism measuring apparatus implemented by this invention and the conventional microorganism measuring apparatus, respectively. In the present invention, the area for collecting microorganisms can be defined. That is, the area of the sampling surface is constant. Therefore, the amount of collected microorganisms is made constant in the conventional microorganism measuring apparatus.

  The specimen is an oral bacteria, and in the conventional method for measuring microorganisms, the area for collecting microorganisms is constant. Therefore, a circular hole is formed in the plastic sheet so as to have the same area (3 cm 2) as the collection surface of the microorganism measuring apparatus implemented in the present invention. Prepared a microbe collection assisting jig. Microorganisms were collected by attaching a microorganism collection assisting jig on the tongue, and collecting the microorganisms on the tongue using a conventional microorganism collecting apparatus. On the other hand, in the microorganism measuring method of the present invention, microorganisms on the tongue were collected as they were.

  In the microorganism measuring apparatus of the present invention, the number of microorganisms was measured using the measuring cell 8. As a conventional microorganism measuring apparatus, microorganisms collected by the above-described microorganism collection auxiliary jig are impregnated and suspended in 5 ml of 0.1 M mannitol solution, and then 50 μl is applied on a blood agar medium and anaerobic for 48 hours. Culture was performed, and the number of microorganisms was calculated by colony count.

  Comparing the measurement results, there was almost no difference in the amount of microorganisms collected between the microorganism measurement method of the present invention and the conventional microorganism measurement method, and the number of microorganisms contained per unit collection area was 1000000 / cm2. It was.

  However, in the conventional microorganism measuring method, when collecting a certain area of microorganisms, it is necessary to prepare the above-mentioned jig. Further, it takes time to dispose of the jig, and the microorganism measuring apparatus shown in the present embodiment There are advantages.

  As described above, according to the microorganism measuring apparatus and the microorganism measuring method according to the present invention, from the collection of the microorganism measurement sample to the measurement, the disposal of the sample and the material possibly contaminated with the microorganism can be performed in a sanitary manner. And can be used as a microorganism measuring apparatus and a microorganism measuring method for examining microorganisms present on the surface of the surface to be collected and microorganisms in the liquid.

Schematic front view of the microorganism measuring device Schematic cross section of measurement cell Schematic view from the opening side of the measurement cell Enlarged view of dielectrophoresis electrode Circuit connection block diagram The figure which shows the approximate front and cross section of the head part provided with the dielectrophoresis electrode. The figure of another form which shows the approximate front and section of the head part provided with the dielectrophoresis electrode.

DESCRIPTION OF SYMBOLS 1 Microorganism measuring apparatus 2 Head part 3 Measurement main body 4 Sampling surface 5 Head side terminal 6 Display means 7 Operation switch 8 Measurement cell 9 Cell structure 10 Seal 11 Liquid holding area 12 Dielectrophoresis electrode 13 Cell side terminal 14 One pole 15 The other Pole 16 gap 17 measuring section 18 computing section 19 control section 20 vibration means

Claims (7)

A microorganism measuring device for collecting and measuring microorganisms,
A head portion having a microorganism collection surface and a dielectrophoresis electrode on the same substrate;
A measurement cell that can be attached to and detached from the head unit capable of holding liquid;
A measurement body;
A microorganism testing apparatus comprising: A microorganism measuring device for collecting and measuring microorganisms,
A head portion having a microorganism collecting surface and a dielectrophoretic electrode formed on the microorganism collecting surface;
A measurement cell that can be attached to and detached from the head unit capable of holding liquid;
A measurement body;
A microorganism testing apparatus comprising: 3. The microorganism testing apparatus according to claim 1, wherein the head part and the measurement main body are detachably connected. Microorganism testing device according to claim 1 to 3, characterized in that the microorganism-collecting surface is made of a porous material effective diameter 0.05 to 5 [mu] m. The microorganism testing apparatus according to any one of claims 1 to 4 , wherein the measurement main body includes vibration means and applies at least linear reciprocation or rotational vibration to the head portion. A method for measuring microorganisms using the microorganism testing apparatus according to claim 1 ,
A microorganism collecting step of bringing a microorganism collecting surface into contact with the surface of a microorganism test object and attaching microorganisms to the microorganism collecting surface;
Impregnating the head part into a measurement cell containing liquid and suspending the microorganisms adhering to the microorganism collecting surface in the liquid;
An impedance measurement step of applying an alternating voltage to the dielectrophoresis electrode and collecting the microorganisms suspended in the measurement cell by the dielectrophoresis force and simultaneously measuring the impedance change at the dielectrophoresis electrode;
Displaying the concentration of microorganisms in the measurement cell from the measured impedance change;
A method for measuring microorganisms, comprising a step of discarding the head part without touching a contaminated part of the microorganism. A method for measuring microorganisms using the microorganism testing apparatus according to claim 1 ,
A microorganism collecting step of bringing a microorganism collecting surface into contact with the surface of a microorganism test object and attaching microorganisms to the microorganism collecting surface;
Impregnating the head part into a measurement cell containing liquid and suspending the microorganisms adhering to the microorganism collecting surface in the liquid;
An impedance measurement step of applying an alternating voltage to the dielectrophoresis electrode, and collecting the microorganisms suspended in the measurement cell by the dielectrophoresis force and simultaneously measuring the impedance change in the dielectrophoresis electrode;
Displaying the concentration of microorganisms in the measurement cell from the measured impedance change;
Simultaneously with the microorganism collection step and / or the impedance measurement step, the vibration means provided in the measurement body vibrates the head portion, and the head portion is discarded without touching the contaminated portion of the microorganism. A method for measuring microorganisms.

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