JP7705763B2 - Extracellular potential measurement plate - Google Patents

Description

The present invention relates to an extracellular potential measurement plate.

Conventionally, a system is known that uses a cell measurement container equipped with an electrode array (micro-electrode array) consisting of multiple electrodes to measure extracellular potentials generated by cellular activity. This system can measure, for example, the extracellular potential of nerve cells. The structure of a conventional cell measurement container is described in Patent Document 1, etc.

The electrode array of the cell measurement container includes a working electrode and a reference electrode. When measuring the extracellular potential, first, a culture solution containing cells (cell suspension) is dripped onto the working electrode. That is, the cell suspension is dripped so as to cover the multiple working electrodes. After the cell suspension is dripped, the multiple cells in the solution sink onto the working electrode and form a cell layer. After the cell layer is formed, the extracellular potential of the cell layer is measured by a measuring device connected to the multiple working electrodes and the reference electrode.

Special Publication No. 2002-523726

After the cell suspension is dropped onto the working electrode, the cells in the droplet spread across the entire bottom surface of the droplet. However, because the size of the working electrode is extremely small compared to the bottom surface of the droplet, most of the cells sink outside the working electrode. As a result, most of the cells do not contribute to the measurement of the extracellular potential, and are wasted. Since IPS cells and the like are extremely expensive, it is desirable to minimize the amount of cells used. However, if the number of cells in the cell suspension is reduced, not enough cells will sink onto the working electrode, making it difficult to effectively measure the extracellular potential.

The object of the present invention is to provide a technology that can effectively measure extracellular potential even when there are only a few cells in a cell suspension.

In order to solve the above problems, a first aspect is an extracellular potential measurement plate comprising at least one working electrode for measuring an extracellular potential, a reference electrode, at least one pair of dielectrophoretic electrodes arranged closer to the working electrode than the reference electrode and to which a voltage is applied to apply a dielectrophoretic force to cells, and a measurement surface onto which a cell suspension containing cells is dropped , wherein the working electrode is located between the pair of dielectrophoretic electrodes and the pair of dielectrophoretic electrodes are arranged on the measurement surface, and the extracellular potential measurement plate further comprises an insulating film covering the entire surfaces of the pair of dielectrophoretic electrodes.

A second aspect is the extracellular potential measurement plate of the first aspect, in which the working electrode and the reference electrode are disposed on the measurement surface.

A third aspect is the extracellular potential measurement plate of the first or second aspect , wherein the working electrode is disposed on the shortest path between the pair of dielectrophoresis electrodes.

A fourth aspect is the extracellular potential measurement plate of the third aspect, wherein at least one of the pair of dielectrophoretic electrodes has a shape whose width narrows toward the working electrode.

A fifth aspect is an extracellular potential measurement plate according to any one of the first to fourth aspects, wherein the measurement surface has an annular droplet control region that passes between the pair of dielectrophoretic electrodes and the reference electrode and surrounds the reference electrode and the pair of dielectrophoretic electrodes, and the contact angle of the droplet control region is larger than the contact angle of an area inside the droplet control region.

A sixth aspect is an extracellular potential measurement plate according to any one of the first to fifth aspects, comprising a plurality of the working electrodes and a plurality of the pairs of dielectrophoretic electrodes, each of the working electrodes being disposed between each of the pairs of dielectrophoretic electrodes.

A seventh aspect is the extracellular potential measurement plate of the sixth aspect, in which the two dielectrophoresis electrodes electrically connected to each other by a common wiring are disposed between the two working electrodes.

An eighth aspect is an extracellular potential measurement plate according to any one of the first to seventh aspects, further comprising a pair of dielectrophoretic sub -electrodes located farther away from the working electrode than the pair of dielectrophoretic electrodes and to which a voltage is applied that applies a dielectrophoretic force to impurities .

According to the extracellular potential measurement plate of the first aspect, cells can be attracted between the pair of dielectrophoretic electrodes by applying a voltage between the pair of dielectrophoretic electrodes, and thus the cells can be collected on the working electrode, so that the extracellular potential can be effectively measured even when the number of cells is small.
According to the extracellular potential measurement plate of the first aspect, cells can be collected by a pair of dielectrophoretic electrodes arranged on the measurement surface.
According to the extracellular potential measurement plate of the first aspect, the pair of dielectrophoretic electrodes is covered with an insulating film, thereby preventing the pair of dielectrophoretic electrodes from coming into direct contact with a liquid. Therefore, even if a high voltage sufficient to move cells is applied between the pair of dielectrophoretic electrodes, electrolysis of the electrode metal can be prevented. Furthermore, by covering the pair of dielectrophoretic electrodes with an insulating film, deterioration and wear of the electrode metal can be prevented.

According to the second embodiment of the extracellular potential measurement plate, the extracellular potential can be measured using a working electrode and a reference electrode arranged on the measurement surface.

According to the extracellular potential measurement plate of the third aspect, cells can be efficiently collected on the working electrode.

According to the extracellular potential measurement plate of the fourth aspect, a strong electric field can be generated near the working electrode, so that the ability of the working electrode to capture cells can be improved.

According to the fifth aspect of the extracellular potential measurement plate, when a cell suspension is dropped onto the measurement surface, the droplets can be maintained inside the droplet control region. In this state, by applying a voltage between the pair of dielectrophoretic electrodes, the cells can be efficiently captured on the working electrode.

According to the extracellular potential measurement plate of the sixth aspect, cells can be collected on the working electrode.

According to the extracellular potential measurement plate of the seventh aspect, the two dielectrophoresis electrodes are connected by a common wiring, so that the space required for wiring can be reduced.

According to the eighth aspect of the extracellular potential measurement plate, when impurities are contained in the cell suspension, the impurities can be moved away from the working electrode by applying a voltage to a pair of dielectrophoretic sub-electrodes that selectively attracts the impurities to the pair of dielectrophoretic sub-electrodes.

FIG. 1 is a schematic perspective view of an extracellular potential measurement plate according to a first embodiment. 2 is a top view showing the measurement surface of the extracellular potential measurement plate shown in FIG. 1 . 3 is a diagram showing a part of a cross section of the extracellular potential measurement plate taken along the line AA shown in FIG. 2. FIG. FIG. 2 is a plan view conceptually showing a state in which a large number of cells are captured on a working electrode. FIG. 13 is a diagram showing a modified example of the dielectrophoretic electrode. 13A to 13C are diagrams showing other modified examples of the dielectrophoretic electrodes. FIG. 11 is a top view showing the measurement surface of an extracellular potential measurement plate according to a second embodiment. FIG. 13 is a top view showing the measurement surface of an extracellular potential measurement plate according to a third embodiment. FIG. 13 is a top view showing the measurement surface of an extracellular potential measurement plate according to a fourth embodiment.

Below, an embodiment of the present invention will be described with reference to the attached drawings. Note that the components described in this embodiment are merely examples, and are not intended to limit the scope of the present invention to these alone. In the drawings, the dimensions and numbers of each part may be exaggerated or simplified as necessary for ease of understanding. In addition, an axis extending in the vertical direction through the working electrode 20 is assumed, and the direction of rotation around this axis is referred to as the "circumferential direction."

1. First embodiment
Fig. 1 is a schematic perspective view of an extracellular potential measurement plate 1 according to the first embodiment. In each of the figures following Fig. 1, only a portion of the wiring connected to the working electrode 20, the dielectrophoretic electrodes 41 and 42, and the reference electrodes 31 and 32 is shown, and detailed structures are omitted.

The extracellular potential measurement plate 1 is a container for containing and holding cells and culture medium and for measuring the extracellular potential. The extracellular potential measurement plate 1 has electrodes on its bottom surface for measuring the electrical properties of the cells or tissue contained within the extracellular potential measurement plate 1.

The extracellular potential measurement plate 1 has a main body 9 having a cup-shaped recess 90, and a measurement surface 8 that constitutes the bottom surface of the recess 90. The extracellular potential measurement plate 1 is a cylindrical container with a bottom, and the main body 9 has one recess 90. The main body 9 has a flat bottom 91 and a side wall 92 that extends upward from the edge of the bottom 91. The upper surface of the bottom 91 forms the measurement surface 8. The extracellular potential measurement plate 1 may be a so-called multi-well plate that has multiple recesses 90.

In the following description, the direction parallel to the measurement surface 8 is referred to as the "horizontal direction," and the direction perpendicular to the measurement surface 8 is referred to as the "vertical direction." Note that it is not essential that the measurement surface 8 be parallel to the horizontal direction when using the extracellular potential measurement plate 1.

The extracellular potential measurement plate 1 is placed on a table or the like so that the measurement surface 8 faces vertically upward. Then, a predetermined amount of a suspension containing cells (hereinafter referred to as a "cell suspension") is dripped onto the measurement surface 8. The amount of cell suspension dripped is, for example, about several μL (e.g., 4 μL). After the cell suspension has been dripped, the extracellular potential measurement plate 1 is left in that position for a certain period of time. During this time, the cells contained in the dripped cell suspension sink in the liquid and form a sheet-like cell layer on the measurement surface 8.

Figure 2 is a top view showing the measurement surface 8 of the extracellular potential measurement plate 1 shown in Figure 1. Figure 3 is a diagram showing a part of a cross section of the extracellular potential measurement plate 1 at a position along the line A-A shown in Figure 2.

As shown in FIG. 2, a working electrode 20, a pair of reference electrodes 31, 32, and a pair of dielectrophoretic electrodes 41, 42 are arranged on the measurement surface 8 of the extracellular potential measurement plate 1. That is, the working electrode 20, the reference electrodes 31, 32, and the dielectrophoretic electrodes 41, 42 are arranged in the recesses 90. Each electrode may be made of, for example, Au, Pt, Ti, or a conductive compound such as titanium nitride (TiN) or indium tin oxide (InSnO), or a laminate structure such as Ti/Al/Ti.

The working electrode 20 is an electrode for measuring the extracellular potential. The shape of the working electrode 20 when viewed from above is square. However, the shape of the working electrode 20 is not limited to a square and can be any shape, such as a rectangle or a circle.

The reference electrodes 31 and 32 are arranged at intervals in the first direction d1, which is a horizontal direction. In a plan view, the reference electrodes 31 and 32 are rectangular extending in a second direction d2, which is horizontal and perpendicular to the first direction d1. The reference electrodes 31 and 32 are arranged with their long sides facing each other. The shape of the reference electrodes 31 and 32 is not limited to a rectangle, and may be any shape such as a square or a circle. The shape of the reference electrodes 31 and 32 may be an arc shape along the circumferential direction. Although not shown in the figure, the reference electrodes 31 and 32 are electrically connected by wiring. The reference electrode is an electrode that provides a reference point for the potential when measuring the extracellular potential. The extracellular potential measurement plate 1 may be provided with only one of the reference electrodes 31 and 32.

The dielectrophoretic electrodes 41, 42 are electrodes for attracting cells (or tissue fragments) in the cell suspension dropped onto the measurement surface 8 between the dielectrophoretic electrodes 41, 42. The dielectrophoretic electrodes 41, 42 are spaced apart in the first direction d1.

In the first direction d1, the working electrode 20 is disposed between the dielectrophoretic electrodes 41 and 42. The dielectrophoretic electrode 41 is located closer to the working electrode 20 than the reference electrode 31. That is, the distance between the working electrode 20 and the dielectrophoretic electrode 41 is narrower than the distance between the working electrode 20 and the reference electrode 31. The dielectrophoretic electrode 42 is located closer to the working electrode 20 than the reference electrode 32. That is, the distance between the working electrode 20 and the dielectrophoretic electrode 42 is narrower than the distance between the working electrode 20 and the reference electrode 32.

The working electrode 20, the reference electrodes 31 and 32, and the dielectrophoretic electrodes 41 and 42 are arranged in a first direction d1. The dielectrophoretic electrode 41 is arranged between the working electrode 20 and the reference electrode 31 in the first direction d1. The dielectrophoretic electrode 42 is arranged between the working electrode 20 and the reference electrode 32 in the first direction d1. It is not essential that the reference electrodes 31 and 32 and the dielectrophoretic electrodes 41 and 42 are arranged in the same direction (first direction d1). For example, the reference electrodes 31 and 32 may be arranged in the first direction d1, and the dielectrophoretic electrodes 41 and 42 may be arranged in a direction intersecting the first direction d1 (for example, the second direction d2).

As shown in FIG. 3, the surfaces of the working electrode 20, the reference electrodes 31 and 32, and the dielectrophoretic electrodes 41 and 42 are covered with an insulating film 50 such as a silicon oxide film (SiOx film). However, a portion of the working electrode 20 is not covered with the insulating film 50 and is exposed to the outside. Also, a portion of the surface of each of the reference electrodes 31 and 32 is not covered with the insulating film 50 and is exposed to the outside. On the other hand, the entire surfaces of the dielectrophoretic electrodes 41 and 42 are completely covered with the insulating film 50 and are not exposed to the outside.

Figure 4 is a plan view conceptually showing how a large number of cells c are collected on the working electrode 20. When forming a cell layer, a cell suspension is first dripped onto the working electrode 20 and the dielectrophoretic electrodes 41 and 42. In this state, as shown in the upper part of Figure 4, a large number of cells c are suspended in a dispersed state within the droplet. After the cell suspension is dripped, an AC voltage according to the electrical characteristics of the cells c in the cell suspension is applied between the dielectrophoretic electrodes 41 and 42. As a result, a dielectrophoretic force acts on the large number of cells c, attracting them between the dielectrophoretic electrodes 41 and 42. Then, over time, as shown in the lower part of Figure 4, the cells c attracted between the dielectrophoretic electrodes 41 and 42 sink and accumulate on the working electrode 20. As a result, a cell layer is formed on the working electrode 20.

As described above, with the extracellular potential measurement plate 1, even if there are only a few cells c in the cell suspension, the cells c can be collected on the working electrode 20 by the dielectrophoretic electrodes 41, 42. This allows a cell layer to be formed on the working electrode 20, making it possible to measure the extracellular potential appropriately and effectively. In addition, when measuring the extracellular potential of expensive cells such as IPS cells, the amount of cells consumed can be reduced, thereby suppressing the cost of measurement.

As shown in FIG. 2, the working electrode 20 is preferably disposed in the center of the dielectrophoretic electrodes 41 and 42. The working electrode 20 is also preferably disposed on the shortest path connecting the dielectrophoretic electrodes 41 and 42. This makes it possible to increase the electric field on the working electrode 20, thereby enabling the cells c to be efficiently collected on the working electrode 20.

Since the dielectrophoretic electrodes 41, 42 are covered with the insulating film 50, the dielectrophoretic electrodes 41, 42 are prevented from coming into contact with the liquid. This makes it possible to prevent electrolysis of the electrode metal even when a high-frequency voltage sufficient to move the cell c is applied between the dielectrophoretic electrodes 41, 42. In addition, because the dielectrophoretic electrodes 41, 42 are covered with the insulating film 50, deterioration and wear of the electrode metal can be prevented.

Figure 5 is a diagram showing a modified example of the dielectrophoretic electrodes 41, 42. Figure 6 is a diagram showing another modified example of the dielectrophoretic electrodes 41, 42. As shown in Figures 5 and 6, the dielectrophoretic electrodes 41, 42 have a shape that narrows toward the working electrode 20. Specifically, in the example shown in Figure 5, the tips of the dielectrophoretic electrodes 41, 42 are pointed. Also, in the example shown in Figure 6, the tips of the dielectrophoretic electrodes 41, 42 are arc-shaped. In either case, a strong electric field can be generated near the working electrode 20, thereby improving the ability of the working electrode 20 to capture cells c.

2, the measurement surface 8 may have a droplet control region 60 for controlling the spread of the droplet. The droplet control region 60 has a circular ring shape. However, the shape of the droplet control region 60 does not necessarily have to be a circular ring shape, and may be a square ring shape, etc. As shown in FIG. 2, the droplet control region 60 is disposed between the dielectrophoretic electrode 41 and the reference electrode 31, and between the dielectrophoretic electrode 42 and the reference electrode 32. The working electrode 20 and the dielectrophoretic electrodes 41 and 42 are disposed in an action region 62 inside the droplet control region 60. The reference electrodes 31 and 32 are disposed in a reference region 64 outside the droplet control region 60.

The surface of the droplet control region 60 is made of, for example, gold (Au). On the other hand, the surface of the action region 62 (excluding the exposed portion of the working electrode 20) is made of an insulating film 50. The contact angle of the planar surface of gold (Au) is approximately 80°. Also, if the insulating film 50 is made of a silicon oxide film, the contact angle of the planar surface of the insulating film 50 is less than 30°. Therefore, the contact angle of the droplet control region 60 (approximately 80°) is larger than the contact angle of the action region 62 (less than 30°).

By making the contact angle of the droplet control region 60 larger than the contact angle of the action region 62, when a droplet is dropped onto the action region 62, it is possible to prevent the droplet from spreading outside the droplet control region 60. In this state, a cell layer can be effectively formed on the action electrode 20 by applying a dielectrophoretic force to the cell c by the dielectrophoretic electrodes 41 and 42.

The planar surface of the reference region 64 (excluding the exposed portions of the reference electrodes 31 and 32) is also covered with the insulating film 50, similar to the action region 62. Therefore, the contact angle of the droplet control region 60 is larger than the contact angle of the reference region 64.

It is not essential that the surface of the droplet control region 60 is made of gold (Au). In other words, the surface of the droplet control region 60 may be made of any material as long as the contact angle of the droplet control region 60 is larger than the contact angle of the action region 62. In addition, if the contact angle of the planar surface of the insulating film 50 is larger than the contact angle of the planar surface of the bottom 91, the droplet control region 60 may be a region covered with the insulating film 50, and the action region 62 may be a region not covered with the insulating film 50, where the bottom 91 is exposed. For example, if the insulating film 50 is made of photosensitive polyimide (contact angle of about 60° to about 70°) and the bottom 91 is made of quartz glass (contact angle of less than 30°), the contact angle of the insulating film 50 will be larger than the contact angle of the bottom 91. In this case, by making the droplet control region 60 a region covered with the insulating film 50 and the action region 62 a region where the bottom 91 is exposed, the contact angle of the droplet control region 60 can be made larger than the contact angle of the action region 62.

<2. Second embodiment>
Fig. 7 is a top view showing the measurement surface 8 of the extracellular potential measurement plate 1A according to the second embodiment. As shown in Fig. 7, the extracellular potential measurement plate 1A has four working electrodes 20 and four pairs of dielectrophoretic electrodes 41, 42 between the reference electrodes 31, 32. That is, the extracellular potential measurement plate 1 has four combinations of the working electrodes 20 and the dielectrophoretic electrodes 41, 42. The four working electrodes 20 are arranged in a matrix with two rows in the second direction d2 and two columns in the first direction d1. Each working electrode 20 is disposed between a pair of dielectrophoretic electrodes 41, 42 in the first direction d1, similar to the working electrodes 20 in the first embodiment.

According to the extracellular potential measurement plate 1A, multiple working electrodes 20 are distributed and arranged on the measurement surface 8, so that the extracellular potential can be measured at different positions. In addition, after dropping the cell suspension, cells c can be collected on each working electrode 20 by applying a predetermined AC voltage between each pair of dielectrophoretic electrodes 41, 42. Therefore, even if the number of cells is small, a cell layer can be formed on each working electrode 20, so that the extracellular potential can be measured appropriately and effectively.

In addition, according to the extracellular potential measurement plate 1A, by applying different AC voltages between each pair of dielectrophoretic electrodes 41 and 42, cells c with different electrical characteristics can be measured for each working electrode 20.
Therefore, by appropriately setting the AC voltage applied to each pair of dielectrophoretic electrodes 41, 42 according to the characteristics such as the size or maturity of the cells c contained in the cell suspension, a large number of cells c with different characteristics can be selectively separated onto each working electrode 20. Then, the separated cells c can be evaluated based on the measurement results of the extracellular potential.

The number of working electrodes 20 is not limited to four, and may be two to three, or five or more. Also, it is not essential that a pair of dielectrophoretic electrodes 41, 42 is provided for one working electrode 20. That is, a pair of dielectrophoretic electrodes 41, 42 may be provided for two or more working electrodes 20. In other words, multiple working electrodes 20 may be disposed between a pair of dielectrophoretic electrodes 41, 42.

<3. Third embodiment>
FIG. 8 is a top view showing the measurement surface 8 of the extracellular potential measurement plate 1B according to the third embodiment. The extracellular potential measurement plate 1B includes four working electrodes 20 and four pairs of dielectrophoretic electrodes 41, 42 between the reference electrodes 31, 32, as in the extracellular potential measurement plate 1A. However, the dielectrophoretic electrodes 42, 42 arranged between the two working electrodes 20, 20 arranged in the first direction d1 are electrically connected by a common wiring 44. In this way, the dielectrophoretic electrodes 42, 42 are connected by the common wiring 44, so that the space required for wiring the multiple dielectrophoretic electrodes 42 can be reduced. In addition, the common wiring 44 can be connected to a power source or GND to control the potentials of the two dielectrophoretic electrodes 42, 42. This simplifies the circuit configuration of the measurement device for measuring the extracellular potential.

<4. Fourth embodiment>
Fig. 9 is a top view showing the measurement surface 8 of the extracellular potential measurement plate 1C according to the fourth embodiment. As shown in Fig. 9, a pair of dielectrophoretic sub-electrodes 71, 72 are arranged on the measurement surface 8 of the extracellular potential measurement plate 1C in addition to the working electrode 20, the reference electrodes 31, 32, and the dielectrophoretic electrodes 41, 42.

The dielectrophoretic sub-electrodes 71, 72 are spaced apart in the first direction d1. The dielectrophoretic sub-electrodes 71, 72 have a rectangular shape extending in the second direction d2 when viewed from above. The dielectrophoretic sub-electrodes 71, 72 have their long sides facing each other in the first direction d1. The dielectrophoretic sub-electrodes 71, 72 may have a shape other than rectangular. The dielectrophoretic sub-electrodes 71, 72 may be made of the same metal as the dielectrophoretic electrodes 41, 42. The surfaces of the dielectrophoretic sub-electrodes 71, 72 are covered with an insulating film 50.

The dielectrophoretic sub-electrode 71 is located closer to the working electrode 20 than the reference electrode 31. That is, the distance between the working electrode 20 and the dielectrophoretic sub-electrode 71 is narrower than the distance between the working electrode 20 and the reference electrode 31. Also, the dielectrophoretic sub-electrode 71 is located farther from the working electrode 20 than the dielectrophoretic electrode 41. That is, the distance between the working electrode 20 and the dielectrophoretic sub-electrode 71 is greater than the distance between the working electrode 20 and the dielectrophoretic electrode 41.

The dielectrophoretic sub-electrode 72 is located closer to the working electrode 20 than the reference electrode 32. Also, the dielectrophoretic sub-electrode 72 is located farther from the working electrode 20 than the dielectrophoretic electrode 42.

The working electrode 20, the reference electrodes 31 and 32, the dielectrophoretic electrodes 41 and 42, and the dielectrophoretic sub-electrodes 71 and 72 are arranged in the first direction d1. The dielectrophoretic sub-electrodes 71 and 72 are located between the reference electrodes 31 and 32 in the first direction d1. The dielectrophoretic sub-electrode 71 is located between the reference electrode 31 and the dielectrophoretic electrode 41 in the first direction d1. The dielectrophoretic sub-electrode 72 is located between the reference electrode 32 and the dielectrophoretic electrode 42 in the first direction d1. The working electrode 20 and the dielectrophoretic electrodes 41 and 42 are disposed between the dielectrophoretic sub-electrodes 71 and 72 in the first direction d1.

If the cell suspension dropped onto the measurement surface 8 contains impurities (bacteria, tissue fragments, etc.) other than the target cells c, an AC voltage that specifically attracts the impurities is applied between the dielectrophoresis sub-electrodes 71, 72. This attracts the impurities to the dielectrophoresis sub-electrodes 71, 72, so that the impurities can be moved away from the working electrode 20. Therefore, the impurities can be prevented from inhibiting the formation of a cell layer on the working electrode 20, and the extracellular potential can be effectively measured.

In the second direction d2, the dimensions of the dielectrophoretic sub-electrodes 71 and 72 are larger than the dimensions of the dielectrophoretic electrodes 41 and 42. Therefore, the dielectrophoretic sub-electrodes 71 and 72 can generate an electric field over a wide range in the second direction d2. Therefore, impurities can be effectively attracted.

The distance between the dielectrophoretic sub-electrodes 71 and 72 is greater than the distance between the dielectrophoretic electrodes 41 and 42. Therefore, the dielectrophoretic sub-electrodes 71 and 72 can attract impurities to the outside of the region between the dielectrophoretic electrodes 41 and 42.

It should be noted that it is not essential that the dielectrophoretic electrodes 41, 42 and the dielectrophoretic sub-electrodes 71, 72 are arranged in the same direction (first direction d1). For example, the dielectrophoretic electrodes 41, 42 may be arranged in the first direction d1, and the dielectrophoretic sub-electrodes 71, 72 may be arranged in a direction intersecting the first direction d1 (e.g., second direction d2).

Furthermore, it is not essential that the reference electrodes 31, 32 and the dielectrophoretic sub-electrodes 71, 72 are arranged in the same direction (first direction d1). For example, the reference electrodes 31, 32 may be arranged in the first direction d1, and the dielectrophoretic sub-electrodes 71, 72 may be arranged in a direction intersecting the first direction d1 (e.g., second direction d2).

Although this invention has been described in detail, the above description is illustrative in all respects and does not limit the invention. It is understood that countless variations not illustrated can be imagined without departing from the scope of this invention. The configurations described in the above embodiments and variations can be combined or omitted as appropriate as long as they are not mutually contradictory.

1, 1A, 1B, 1C Extracellular potential measurement plate 8 Measurement surface 20 Working electrode 31, 32 Reference electrode 41, 42 Dielectrophoretic electrode 44 Wiring 50 Insulating film 60 Droplet control area 71, 72 Dielectrophoretic sub-electrode c Cell

Claims (8)

An extracellular potential measuring plate,
at least one working electrode for measuring an extracellular potential;
A reference electrode;
At least one pair of dielectrophoretic electrodes located closer to the working electrode than the reference electrode and to which a voltage is applied to apply a dielectrophoretic force to the cells;
A measurement surface onto which a cell suspension containing cells is dropped;
Equipped with
the working electrode is located between the pair of dielectrophoretic electrodes;
the pair of dielectrophoretic electrodes is disposed on the measurement surface,
The extracellular potential measuring plate comprises:
an insulating film covering the entire surfaces of the pair of dielectrophoretic electrodes;
The extracellular potential measuring plate further comprises: 2. The extracellular potential measurement plate according to claim 1,
An extracellular potential measurement plate, wherein the working electrode and the reference electrode are disposed on the measurement surface. The extracellular potential measuring plate according to claim 1 or 2,
An extracellular potential measuring plate, wherein the working electrode is disposed on the shortest path between the pair of dielectrophoresis electrodes. 4. The extracellular potential measuring plate according to claim 3,
At least one of the pair of dielectrophoretic electrodes has a shape that narrows toward the working electrode. The extracellular potential measurement plate according to any one of claims 1 to 4,
The measurement surface is
a ring-shaped droplet control region that passes between the pair of dielectrophoretic electrodes and the reference electrode and surrounds the reference electrode and the pair of dielectrophoretic electrodes;
An extracellular potential measurement plate, wherein the contact angle of the droplet control region is larger than the contact angle of an area inside the droplet control region. The extracellular potential measurement plate according to any one of claims 1 to 5,
A plurality of the working electrodes;
A plurality of pairs of dielectrophoretic electrodes;
Equipped with
An extracellular potential measuring plate, wherein each of the working electrodes is disposed between each of the pairs of dielectrophoretic electrodes. 7. The extracellular potential measuring plate according to claim 6,
An extracellular potential measuring plate, wherein the two dielectrophoresis electrodes electrically connected to each other by a common wiring are disposed between the two working electrodes. The extracellular potential measurement plate according to any one of claims 1 to 7,
a pair of dielectrophoretic sub-electrodes located farther from the working electrode than the pair of dielectrophoretic electrodes, to which a voltage is applied for applying a dielectrophoretic force to impurities;
The extracellular potential measuring plate further comprises:

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