JPH11223596A - Reagent mixing device - Google Patents

Abstract

(57) [Summary] A flow for improving the stability of the operation of an analyzer with a complicated machine operation, particularly the parallel processing type analyzer, eliminating waste in the operation, and shortening one sample time. A through cell and a channel system including the same are provided. A part (1) of the sample flow path is made thinner, the narrow part of the inner diameter is made (2) branched, and (3) one end of the branched part is connected to a storage container of a solution to be mixed, for example, a washing liquid. . The reason for reducing the inner diameter is to introduce the mixed solution into the sample flow channel using Bernoulli's law.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for mixing a fluid in a fine channel with another fluid, and more particularly to a flow-through cell for quantifying trace substances in a sample solution, and an analysis using the same. Related to the device.

[0002]

2. Description of the Related Art In the field of immunoassay, a fluorescent method, a chemical method, and the like are used as analytical methods for measuring the concentration of a very small amount (10 ⁻¹⁴ mol · dm ⁻³ or less) of a sample in a sample using a luminescent label. Luminescence method (Chemiluminescence method, CL method) and electrochemiluminescence method (Electrochemiluminescenc)
e method and ECL method), which are widely used. The fluorescence method detects light emission from the sample due to light excitation, the CL method detects light emission from the sample in the presence of a catalyst such as an oxidizing agent, and the ECL method detects light emission from the sample when a voltage is applied to the sample. . In each of these methods, a luminescent reagent is bound to a substance to be measured such as a hormone, a tumor marker, a drug, or a DNA molecule by an antigen-antibody reaction, and the luminescence derived from the luminescent reagent is quantified. High detection sensitivity. In the ECL method, an electrode needs to be brought into contact with a sample to be measured, and measurement is generally performed while flowing the sample into a flow-through cell. In the following description of this specification, this cell is called an ECL flow-through cell,
The sample measured by the flow-through cell is called an ECL sample.

[0003] Known examples of the ECL flow-through cell are described in, for example, JP-A-7-209189 and JP-A-7-248330. In a conventional ECL flow-through cell,
Until the measurement of one ECL sample is completed, the next EC
The L sample is waiting for measurement. In the following description of the present specification, the measurement time of one ECL sample is referred to as one cycle time.

[0004] In the flow-through cell of the prior art, in particular, in the ECL flow-through cell described in JP-A-7-209189 and JP-A-7-248330, (1) an ECL sample is introduced into the ECL flow-through cell. (2) A voltage is applied to the ECL sample to measure the emission value, and (3) the inside of the flow-through cell is washed while discharging the ECL sample in preparation for the next measurement. One cycle time requires at least the above three parts of (1) sample introduction, (2) measurement, and (3) discharge cleaning.

A conventional flow-through cell is disclosed in Japanese Unexamined Patent Publication No. 7-2
As shown in FIG. 1 of No. 48330, the flow channel for introducing the sample into the cell is constituted by a single tube without branching. This is because the absence of branching prevents the flow from stagnating at the branch point. If there is a blockage in the flow, when a sample, especially a sample containing blood, is introduced into the flow channel, large impurities contained in the blood are likely to remain at the branch point and interfere with subsequent measurements. It is because there is.

Unbranched tubes are the simplest channels and have been widely used to date. However, some apparatuses which have been subjected to pretreatment such as separation of only serum components in advance use a branched tube. As a technique in another field, in HPLC (High Performance Liquid Chromatography), many branched flow paths are used. See Japan Society for Analytical Chemistry, Kanto Chapter, "High Performance Liquid Chromatographic Analysis", Sangyo Tosho, 1982. Therefore, in an immunoanalyzer, a branched tube can be used for a sample from which a serum component is separated.

[0007]

In a typical immunological analyzer, it is necessary to mix one or more kinds of reaction reagents with a sample such as serum. Especially for flow-through cells, 1
After measuring a sample, and before measuring the next sample,
In order to clean the inside of the flow-through cell, it is necessary to separately introduce a cleaning liquid into the flow-through cell.

In the conventional method, a plurality of liquids, such as a sample, a reaction reagent, and a washing liquid, stored in separate containers are aspirated by one unbranched tube. Therefore, the suction port of the tube is mechanically operated up to the container storing each liquid, called a suction port moving mechanism.
A mechanism was needed. And the sample and the reaction reagent
Since the mixing ratio must often be strictly controlled, a mechanism called a dispensing mechanism for strictly controlling the suction amount of the tube is required. The dispensing mechanism includes, for example, a syringe, a valve, and a high-precision motor.

However, in the conventional apparatus in which all the liquids are suctioned by a single tube having no branch, even a liquid such as a cleaning liquid which does not require a strict control of the suction amount is suctioned using the dispensing mechanism. Must-have. If it takes, for example, one second for the suction port operation mechanism to move the suction port to the cleaning liquid storage container in order to aspirate the cleaning liquid, it takes more than ten minutes to continuously measure 1,000 samples. It will be a difference. This difference hinders an increase in the speed of the apparatus. In particular, in order to realize a parallel processing type analyzer that will be developed in the future and that performs simultaneous measurement of a plurality of samples, for example, a parallel processing type analyzer having two or more inlet operating mechanisms and operating simultaneously. Behavior should be avoided as much as possible. This is because the parallel processing itself requires a complicated operation, so that there is less room to include an unnecessary operation.

An object of the present invention is to solve the above-mentioned problems in the prior art, to increase the speed of the apparatus, in particular, to eliminate waste in the operation of the parallel processing type analyzer, improve the stability of the apparatus operation, and An object of the present invention is to provide a flow-through cell which shortens one sample time and a flow path system including the same.

[0011]

According to the reagent mixing apparatus of the present invention, (1) the inside diameter of a part of the sample flow path through which the sample flows is reduced, and the narrow part is divided into (2) branches, and (3)
It is characterized in that the branched one end is connected to a storage container for a solution to be mixed, for example, a cleaning solution. The reason for reducing the inner diameter is to use Bernoulli's law to mix the mixed solution,
This is for introduction into the sample channel. Bernoulli's law states that
The flow velocity is q, the gravitational acceleration is g, the pressure is p, the density of the solvent is ρ, and the potential energy is z.

[0012]

[Number 1] ^{q 2 / 2g + p / ρg} + z = const. ... (1) If the total flow rate per unit time is the same, by narrowing a portion of the inner diameter of the sample flow path, the flow rate of the portion becomes faster ( q increases). Then, according to equation (1), if the height is constant (z is constant), the pressure decreases (p decreases), and the solution to be mixed, for example, the cleaning liquid, flows in from the branched side path. This branching point may be inside the ECL flow-through cell or in the middle of a tube for introducing a sample into the ECL flow-through cell. When unnecessary, it is necessary to install a valve at the branch point so that the solution is not supplied from the branched side path.

[0013] Even if the inner diameter is not reduced, the pressure difference between the storage container for the cleaning liquid and the flow path is generated by increasing the flow velocity in the flow path, and the cleaning liquid is introduced into the flow path. However, if the inner diameter of the flow path is not reduced, the flow velocity inside the flow path becomes too large, and the formation of turbulent flow is promoted.

From the branch point, not only the cleaning liquid,
Bubbles can be introduced. By switching the valve and alternately introducing the cleaning liquid and the air, the cleaning liquid containing bubbles is introduced into the flow channel. Then, (1) the bubble collides with the inside of the flow path, thereby improving the cleaning efficiency. (2)
Bubbles disappear quickly because bubbles actively foam detergent.
(3) Even if the amount of liquid used is small, the same cleaning effect as when no bubbles are introduced can be obtained.

The method of introducing a mixed solution utilizing Bernoulli's law can be used in a micro detector (micro machine) having a size of about micrometers. In the current micromachine, the thickness of the flow path is constant, and the mixing of the reaction solution uses a diaphragm valve. By reducing the inner diameter of the mixing section in the flow channel, the reaction solution can be mixed even if the solution speed in the flow channel is reduced. Therefore, the formation of turbulence in the flow channel can be suppressed, and the mixing ratio can be controlled with higher precision.

[0016]

FIG. 1 shows an embodiment of the present invention.
It is a figure including a partial section showing the composition of the ECL flow-through cell which has a mixing point inside the cell. Using an ECL flow-through cell, samples of hormones, tumor markers, drugs, enzymes, cytokines, nucleic acids, and the like can be quantified by the ECL method. While flowing the sample through the ECL flow-through cell 1,
The measurement is performed by bringing the sample into contact with the working electrode 2. When a sample is detected, the working electrode 2 and a counter electrode 3 facing the working electrode 2 are detected.
During this period, a potential higher than the standard electrode potential of the labeling substance used for ECL analysis is applied.

The ECL flow-through cell 1 has a sample inlet 4 for introducing a solution containing an object to be measured and a sample outlet 5 for discharging. A mixing point 6 is provided between the sample inlet 4 and the working electrode 2 for introducing the mixed solution into the ECL flow-through cell 1. At the mixing point 6, a mixed liquid such as a cleaning liquid is introduced through the mixed liquid inlet 7. ECL flow-through cell 1
The internal cross-sectional area decreases continuously from the sample inlet 4 to the mixing point 6 of the ECL flow-through cell 1 and increases continuously from the mixing point 6 toward the sample outlet 5.

When the cross-sectional area is rapidly changed near the mixing point 6, that is, when a sudden expansion pipe and a sudden reduction pipe are formed, a turbulent flow occurs near the mixing point 6 and the pressure loss increases. This has to be avoided.

In the prior art ECL flow-through cell,
The measurement target hormone existing in the liquid is immobilized on the surface of the magnetic beads by an antigen-antibody reaction, and the magnetic beads are held on the surface of the working electrode 2 by the magnet 9. The magnet 9 is not indispensable in the present invention, but is indispensable when magnetic beads are used. The magnet 9 is an electromagnet or a permanent magnet. The magnetic beads trapped on the working electrode 2 of the ECL flow-through cell 1 by the magnetic force of the magnet may cut off the current to the electromagnet after the analysis is completed, or may mechanically switch the permanent magnet to the ECL.
By decreasing the magnetic force away from the flow-through cell 1,
It is discharged from the ECL flow-through cell 1. A photodetector 8 for detecting light emitted from the luminescent material by the ECL reaction was provided near the working electrode 2. Light emitted from the luminescent substance passes through the space between the counter electrodes 3 and is detected by the photodetector 8.

FIG. 2 shows an ECL having a mixing point inside the cell.
FIG. 2 is a configuration diagram including the entire flow path system from the introduction of an ECL sample to the discharge through a flow-through cell.

In this configuration, two types of liquids, specifically, the sample liquid 21 and the reaction reagent 22, are introduced from the suction port 23, and one type of mixed liquid 25 is introduced into the cell. Since both the sample solution 21 and the reaction reagent 22 are sucked, a suction port moving mechanism 24 is provided. The mixed liquid, particularly the cleaning liquid, is put in the mixed liquid reservoir 25. If it is necessary to increase the accuracy of the suction amount, use a syringe 26 without using a motor.
It is good to use.

The sample solution 21 or the reaction reagent 22 is
When introducing into the CL flow-through cell, the solenoid valve A27
Is opened, the solenoid valve B28 is closed, and the solenoid valve C29 is closed. Further, when the liquid in the mixed liquid reservoir 25 is introduced into the ECL flow-through cell, the electromagnetic valve A27 is opened, the electromagnetic valve B28 is closed, and the flow path with the mixed liquid reservoir 25 is opened in the electromagnetic valve C29. When air bubbles are introduced into the ECL flow-through cell, the solenoid valve A27 is opened, the solenoid valve B28 is closed, and the solenoid valve C29 is connected to the air inlet 201. When the washing liquid is stored in the mixed liquid reservoir 25, the suction port 23 is set at a position where the reaction reagent 22 is sucked. Then, a liquid in which the reaction reagent and the washing liquid are mixed is introduced into the ECL flow-through cell 1. Although the concentration of the washing solution becomes thinner because it is mixed with the reaction reagent 22, the concentration of the washing solution in the mixed solution reservoir 25 and the cross-sectional area at the mixing point 6 are adjusted, so that the reaction solution and the washing solution can be suitably mixed. The mixing ratio can be realized and the cleaning ability can be maintained.

When the liquid is discharged from the ECL flow-through cell, the discharged liquid is moved between the solenoid valve A27 and the solenoid valve B28, the solenoid valve A27 is closed, the solenoid valve B28 is opened, and the syringe operation is performed. Do. In particular, when the cleaning liquid is introduced into the flow-through cell 1, the mixed liquid reservoir 25 and the solenoid valve C2
In addition to providing a valve between 9 and sucking the mixture,
If the air can be sucked from the outside through the air inlet 201 and switching between the mixed liquid suction and the air suction can be performed, the air and the cleaning liquid are appropriately mixed, so that the cleaning efficiency is further improved. be able to.

FIG. 3 is a configuration diagram of a flow path system having a mixing point upstream of the ECL flow-through cell. EC of mixing point 31
It has the same configuration as FIG. 2 except that it is provided upstream of the L flow-through cell. If the cross-sectional area at the mixing point 31 in FIG. 3 can be adjusted, it is possible to actively control the inflow amount of the mixed liquid from the mixed liquid reservoir 25.

FIG. 4 is a diagram showing the mixing point 3 in the embodiment of FIG.
FIG. 2 is a conceptual diagram of a mechanism for actively controlling the flow channel cross-sectional area of No. 1; FIG. 2 is a cross-sectional view of a tube having a thickness of several mm or less. The sample flows into the mixing point 31 from the inlet 41 and is discharged from the outlet 42. FIG. 4A shows a state in which the amount of the mixed solution inflow 44 is reduced while the flow path cross-sectional area is kept large.
On the other hand, FIG. 4B shows a state in which the flow path cross-sectional area is reduced and the amount of the mixed solution inflow 44 is increased.

As the cross-sectional area of the flow path at the mixing point 31 decreases, the flow velocity of the liquid increases. Then, the pressure at the mixing point 31 decreases according to Bernoulli's law, and the amount of the mixed solution inflow 44 increases. The active control of the flow path cross-sectional area is performed by injecting air or a liquid such as oil or water from the outside into the vacuoles 43 provided at the mixing point 31. The material forming the vacuoles 43 is a polyurethane fiber or rubber having a high elongation. Polyurethane fiber elongation 450-800
%, Strength is hardly reduced under strong acids and alkalis, so it is an excellent material.

As the rubber, chloroprene rubber, butyl rubber, acrylic rubber, chlorosulfonated polyethylene rubber, silicone rubber, fluorine rubber and the like can be used. When injecting air into the vacuole 43, it is particularly desirable to use butyl rubber having a large air holding power. When oil is injected into the vacuoles 43, it is particularly preferable to use acrylic rubber or fluoro rubber having good oil resistance. The wall material that separates the vacuole 43 from the flow path may be Teflon or the like forming another part of the flow path. In order to make the wall material elastic,
The thickness of the wall may be thinner than other parts of the flow path.
According to this method, the inflow amount of the mixed solution can be adjusted while maintaining the flow velocity in the flow channel at a speed at which turbulent flow is not formed.

As described above, unnecessary operation of the suction port operation mechanism can be reduced by using this method, which can contribute to speeding up the measurement. In particular, in order to realize a parallel processing-type analyzer, unnecessary operations must be avoided as much as possible.

FIG. 5 shows the example shown in FIGS.
FIG. 4 is a conceptual diagram when the present invention is applied to a microchannel system. That is, an embodiment in which an analyzer for measuring the result of a chemical reaction such as a color reaction or an antigen-antibody reaction generated by mixing a plurality of liquids with a sample to be measured by a detector is realized by a microchannel system. It is. The thickness of the channel is in the order of micrometer to millimeter. The microchannel system can be formed, for example, using silicon as a material by using current semiconductor processing technology. It is considered that the present invention is often applied to a disposable sensor for each measurement.

FIG. 5 (A) is a channel shape diagram in which a part including a mixing point 52 where a mixed solution is introduced is extracted from the micro channel system. FIG. 5B is a three-dimensional view in which only a rectangular portion surrounded by a dotted line in FIG. 5A is enlarged. The measurement sample passes from the sample inflow 51, passes through the mixing point 52, and is discharged from the sample outlet 54. The velocity at the time of the inflow 51 of the measurement sample is determined, and the mixing point 52 and the mixed liquid inflow path 5 are determined.
By adjusting the thickness of 3, the mixing ratio of the mixed liquid reservoir A55, the mixed liquid reservoir B56, and the mixed liquid reservoir C57 can be set to a predetermined ratio. After the mixed solution flows, the mixed solution reservoir A
A valve 58 is provided to stop further inflow from the mixed liquid reservoir B56 and the mixed liquid reservoir C57. This figure 5
If the cross-sectional area at the mixing point 52 can be adjusted, it is possible to actively control the inflow amount of the mixed liquid from the mixed liquid reservoirs 55, 56, and 57 even in the microchannel system.

FIG. 6 shows an example of the embodiment of FIG.
FIG. 2 is a conceptual diagram of a mechanism for actively controlling a flow path cross-sectional area of No. 2; If a part of the wall of the mixing point 52 is constituted by the piezo element 62, a voltage is applied from the wiring 63 to the piezo element 6.
2 can be deformed to change the cross-sectional area at the mixing point.

[0032]

According to the reagent mixing apparatus of the present invention, (1) the inside diameter of a part of the sample flow path through which the sample flows is reduced, the narrow part is (2) branched, and (3) the branched one end is connected. It is combined with a storage container for the solution to be mixed, for example, a cleaning liquid. By reducing the inside diameter of a part of the sample flow path, the mixed solution is introduced into the sample flow path using Bernoulli's law. In particular, in a parallel processing type analyzer requiring complicated mechanical operations, unnecessary operations can be reduced, so that the stability of the device operation is improved, and a flow-through cell which shortens one sample time and the flow-through cell are included. A channel system can be realized.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of an electrochemiluminescent flow-through cell according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a flow channel system of an electrochemiluminescence flow-through cell according to an example of the present invention.

FIG. 3 is an overall configuration diagram of an electrochemiluminescence flow-through cell flow path system according to an example of the present invention.

FIG. 4 is a conceptual diagram of a mechanism for controlling a flow path cross-sectional area at a mixing point in the embodiment of the present invention.

FIG. 5 is a conceptual diagram when the present invention is applied to a microchannel system.

FIG. 6 is a conceptual diagram of a mechanism for controlling a cross-sectional area of a channel when the present invention is applied to a microchannel system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electrochemiluminescence flow-through cell 2 ... Working electrode 3
... Counter electrode, 4 ... Sample inlet, 5 ... Sample outlet, 6 ... Mixing point (inside cell), 7 ... Mixed liquid inlet, 8 ... Photodetector (photomultiplier, photodiode, etc.), 9 ... Magnet, 21
... sample liquid, 22 ... reaction reagent, 23 ... sample suction port, 24 ... suction port moving mechanism, 25 ... mixed liquid reservoir, 26 ... syringe, 27 ... solenoid valve A, 28 ... solenoid valve B, 29 ... solenoid valve C, 30 liquid outlet, 31 mixing point (upstream of cell), 4
Reference Signs List 1 ... sample inflow, 42 ... sample outflow, 43 ... vacuum, 44 ... mixture inflow, 51 ... sample inflow (micro flow path), 52 ... mixing point (micro flow path), 53 ... mixture liquid inflow path (micro flow) Road), 54
... sample outflow (micro flow path), 55 ... mixed liquid reservoir A, 56 ... mixed liquid reservoir B, 57 ... mixed liquid reservoir C, 58 ... valve, 61 ... sample inflow (micro flow path), 62 ... piezoelectric element (piezo) Element), 6
3. Wiring, 64: Sample outflow (micro flow path), 201: Valve.

Claims (7)

[Claims] 1. The method according to claim 1, wherein the sample is sucked and discharged.
Part of the sample flow path where the sample flows, (1) narrow the inner diameter, (2) branch the narrower part, and (3) connect the branched end to the solution to be mixed, and use Bernoulli's law A reagent mixing device for introducing the solution to be mixed into the sample channel. 2. The reagent mixing apparatus according to claim 1, further comprising a switching valve for alternately introducing the solution to be mixed and air into the sample flow path. 3. The reagent mixing device according to claim 1 is provided in a flow-through cell, and the cross-sectional area of the flow-through cell is continuously changed from the sample inlet of the flow-through cell toward the branch point according to claim 1. 3. A flow-through cell having a flow path shape that is made smaller in size and continuously increases from the branch point according to claim 1 toward the sample outlet of the flow-through cell. 4. The reagent mixing device according to claim 1 is provided inside the flow path on the way from the sample suction port to the flow-through cell, and the cross-sectional area of the flow path from the sample suction port toward the branch point according to claim 1 is increased. An analyzer having a flow path shape that is continuously reduced and the flow path cross-sectional area is continuously increased from the branch point to the flow-through cell according to claim 1. 5. The reagent mixing device according to claim 1, further comprising means for actively controlling the cross-sectional area of the flow path at the branch point. 6. The reagent mixing apparatus according to claim 5, wherein the active control of the cross-sectional area of the flow path is performed by injecting a fluid such as air, oil, or water from the outside into the vacuole formed in the branch portion. . 7. The reagent mixing device according to claim 1 is provided in a microchannel having a width of several micrometers made of silicon or the like, and the cross-sectional area of the branch point according to claim 1 is externally determined by using a piezoelectric element. 2. The reagent mixing device according to claim 1, wherein control is performed by applying a voltage from the reagent.