JPH0731204B2 - Immunoassay device and method - Google Patents

Description

FIELD OF THE INVENTION The present invention relates generally to the field of immunoassays, and more particularly to immunoassay devices and methods and new reaction vessels for use therein.

BACKGROUND Heterogeneous immunoassays are well known and accepted in the art to provide greater analytical sensitivity than homogeneous immunoassays. Heterogeneous competitive immunoassays commonly require a so-called solid phase or carrier retained in the reaction vessel. Unknown amount of analysis items such as drugs (analyt
A patient sample, which may include e), is added to the container, for example, with a known amount of analyte labeled with the enzyme. Labeled or labeled analytes and unlabeled or unlabeled analytes compete for binding sites on the solid support. At equilibrium, the amount of labeled analyte bound to the solid support is related to the concentration of the unlabeled analyte. When the competitive reaction reaches equilibrium, the patient sample and unreacted labeled analytes are removed from the reaction vessel, leaving the solid support with only the remaining unbound labeled analytes. Instead, it is cleaned to completely remove the patient sample.

The substrate is then added to the reaction vessel and catalyzed by oxygen to produce a measurable substance such as a fluorescent molecule. After the catalytic reaction is complete, the substrate is removed from the reaction vessel and the measurable substance is quantified using, for example, fluorescence photometry. The concentration of the unknown analyte in the patient sample can then be determined using a predetermined calibration relationship that relates the amount of measurable substance to the amount of unlabeled analyte in the sample.

Despite the excellent sensitivity of heterogeneous immunoassays, the typical assay just described requires fairly sophisticated work of the reaction vessel, which involves multiple fluid transports. In particular, the labeled analyte and patient sample must be removed, the solid support must be washed,
Substrate must be added and then removed. The work involved is time consuming, difficult to automate, and is an obvious disadvantage when it is desired to use the heterogeneous immunoassay for high volume applications such as in hospital clinical laboratories.

One approach to simplifying the work involved in heterogeneous immunoassays was to configure the solid support as a filter at the bottom of the reaction vessel. Such filters are
The patient sample is wetted with the labeled analyte flowing through the reaction vessel and filter, resulting in a flow through the wash solution and substrate. The catalyzed material in the substrate precipitates directly on the filter media, eg
Leaves a colored stain on the filter media. However, such colored stains are difficult to quantify accurately, and very often, the filter media will show the presence or absence of colored stains in the patient sample indicating the presence or absence of analytes. Simply inspected to determine. Thus, although such filter approaches have been used for heterogeneous immunoassays, the advantages of quantitative determination of analyte concentration, which would otherwise be possible in heterogeneous immunoassays, are not recognized.

The use of a filter as part of a reaction vessel also allows for other forms of immunoassay, in particular, the filter may be a hydrophobic (herein hydrophobic or hydrophobic) material may be used. It is known in immunoassays. When a reaction occurs in the reaction vessel of such a radioimmunoassay, pressure is applied to the fluid in the vessel to wet the filter and force fluid out of the reaction vessel through the filter. Once the filter has been moistened, it is then not possible to terminate the flow of fluid through the filter. Such properties of the filter material are not detrimental to radioimmunoassay in that such analysis requires fluid to be drawn from the reaction vessel only through the filter. However, if such a filter is used for enzyme immunoassay,
It would also be necessary to provide an external valve to stop the flow of fluid through the filter when the filter is moistened. Such external valves add considerable cost and complexity to a heterogeneous immunoassay device, especially if the device is automated and the individual reaction vessels should be discarded after a single use.

SUMMARY The present invention is directed to an apparatus and method that overcomes the limitations and disadvantages of the prior art. This system and method greatly simplifies the work required for the reaction vessel and is particularly convenient for automated equipment.

Both the system and method of the present invention involve the use of reaction capsules that employ filters of hydrophobic materials with previously unrecognized and unused properties. When the filter is in a hydrophobic state, it becomes hydrophilic due to the addition of a pressure difference across the filter, and the fluid flow through the filter causes the pressure difference between one side of the filter and the other It can be initiated by the reaction of pressure difference). Conveniently, the flow of fluid may be terminated by returning the filter to a hydrophobic state by flowing a gas through the filter. The novel application of the filter according to the invention can be formed integrally with the reaction capsule,
And further, to create a cheap and reliable valve that allows performing heterogeneous immunoassays without the cumbersome fluid handling equipment and techniques known in the prior art. The inexpensive nature of the reaction capsules will cause the user of this system and method to dispose of the capsules after use, further simplifying the heterogeneous immunoassay and, as was common in the prior art, a single dose. Substantially reduce the potential for residue contamination during the continuous analysis performed in the reaction vessel.

The system may further include a wheel or carousel supporting a plurality of reaction capsules. The wheel is supported at its center by an offset cam rotatable by an electric motor. The operation of the electric motor creates a vortex effect in the reaction capsule carried by the wheel to sufficiently agitate the fluid contained in the reaction vessel. Single room 2
A novel pump at the inlet can be employed in the system to pass fluid and then gas through the filter in the reaction capsule. Thus, the liquid and gas pumping action is combined in a single assembly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an immunoassay device according to the present invention.

2 is a view of a reaction capsule according to the present invention useful in the system of FIG. 1, shown in cross section along its central axis.

FIG. 3 is a sectional view of the reaction capsule of the present invention taken along line 3-3 of FIG.

FIG. 4 is a side view of the wash station taken along line 4-4 of FIG.

FIG. 5 is a side view of the reading station taken along line 5-5 of FIG.

FIG. 6 is a schematic cross-sectional side view of a portion of a single chamber pump useful in the system of FIG.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1-3, a system 10 in accordance with the present invention.
Includes a horizontal turntable 12 supporting a plurality of reaction capsules, generally indicated at 14. Each capsule 14 comprises a lower part 18, an upper part 20 and a filter 22. The upper portion 20 includes a cylindrical tubular portion 24 that is open at both ends and has an annular flange 26 that projects outward at the upper end.

The lower portion 18 is a cylindrical base having an inner surface 30 formed to closely receive an outer surface at the lower end of the tubular portion 24.
Including 28. The inner side surface 30 is connected to a tapered surface 32 which is inclined outward to connect the base portion 28 to the cylindrical wall portion 34. The upper end of the cylindrical wall portion 34 is formed as an annular flange 36 protruding outward.

The base portion 28 is inclined downward to form a funnel portion 38,
An internal passage 40 is formed that opens at the lower end.

The base 28 includes a plurality of supports 44 extending from the inner wall of the base 28 to the passage 40, and a plurality of struts 46 between the supports 44 also extending from the wall of the base 28 to the passage 40. Supports 44 and struts 46 each have a coplanar support surface 48 formed to support filter 22. The inner surface 30 comprises a plurality of semi-circular grooves 50 extending from the tapered surface 32 to approximately half the distance between the surface 32 and the support surface 48.

The filter 22 is sandwiched between the annular surface 52 in the base 28 and the annular edge at the bottom of the cylindrical tubular portion 24. The annular surface 52 serves as two raised rings 5 which serve to grip the filter 22.
Can have 4, 56. The upper part 20 is rigidly fixed in the lower part 18 for fixing the filter 22 in the capsule 14.

According to the invention, the filter 22 comprises an upper part 20 and a filter 22.
It is selected from a hydrophobic material that keeps the liquid in the reaction chamber 58 defined by and. In the disclosed embodiment, the volume of reaction chamber 58 is approximately 1 milliliter. Reaction chamber 58 may also hold a solid support useful for immunoassays. By making the filter 22 hydrophobic, water-like liquid at atmospheric pressure in the capsule does not wet the filter 22 and thus the filter 22 retains such liquid in the capsule. Conveniently, when pressure is applied to the reaction chamber 58, the liquid wets the filter 22, causing the liquid to flow through the passage 40 and the funnel extension 38. To stop the flow of fluid, a gas is flowed through the reaction chamber 58, the filter 22 and the passages 40 to remove the dampening liquid from the filter's slits, thus leaving the filter free or hydrophobic. Return to the state of. When returned to the hydrophobic state, the filter 22 will retain the liquid in the capsule 14 at atmospheric pressure again.

Thus, the filter 22 is simple and effectively forms a low cost liquid valve with no moving parts, which is an important advance, especially with respect to non-uniform immunoassays, as described above. In the embodiments disclosed herein for reagents such as water and wash solutions, the filter 2 is approximately 0.127 mm (0.005 inch) thick and has a maximum functional slit diameter of approximately 10 to 20 microns.
Made from a sintered tetrafluoroethylene matrix coating material. Such materials are available from Chemplast Incorporated (Ch
emplast Inc.) from Chemplast Publishing number C100-10
As described in M680N, catalog number A-14
5, available under the trade name of "Zytex", type E249-122.

Referring again to FIG. 1, the reaction capsule 14 is placed on the turntable in suitable restraining means 60 at the loading station 61.
Accepted to 12. The restraint means 60 includes a plurality of openings 62 formed vertically through the turntable 12. Each opening
62, when the capsule 14 is placed on the turntable 12,
The lower surface of the flange 36 is shaped to receive the lower portion 18 of the capsule 14 so that it leans against the upper surface of the turntable 12.

The turntable 12 of the system 10 is at its center and the capsule 14
In order to create a vortex mixing effect, as described later in
It is supported by an offset or eccentric cam 66. A flexible belt 68 extends from around the periphery of the rotary table 12 to a drive pulley 74 which is guided by idler wheels 70 and 72 and is rotationally driven by a stepper motor 76.

The system 10 includes a sample transport subsystem 78 that includes a track 80 that supports a moveable probe 82. sub-system
78 is equipped with suitable drive means for performing the following movements. That is, moving the probe 82 along the track 80, lowering the probe 82 into a selected one of a plurality of sample cups 84, aspirating a fixed amount of sample into the probe 82, rotating the probe 82 on a rotary table. Moving to sample delivery station 86 above 12, lowering probe 82 into capsule 14 at station 86, and delivering aspirated sample into capsule 14 at sample delivery station 86. Subsystem 78 also provides a fixed volume of sample to sample supply station 86.
A cleaning station 88 for cleaning the probe 82 after being dispensed at.

System 10 also includes a reagent delivery subsystem 90, similar to sample delivery system 78. The reagent transfer subsystem includes a truck 92, a movable probe 94, and a cleaning station.
96 and all of these, including multiple reagent cups 97 to 1
Or set the exact amount of multiple reagents in the reagent supply station.
It is configured for delivery to capsule 14 located at 98.

It will be appreciated that the sample and reagent delivery subsystems 78, 90 may be of conventional description, as is well known in the automated clinical equipment arts. Subsystem 78
And 90 using a single probe head that has been transferred to an XY orthogonal system above the sample cup 84, reagent bottle 96 and single supply station 86 or 98.
Equivalent means, such as replacing with a -Y subsystem, would also be appropriate.

The system 10 includes a capsule washing station 100, as seen in FIG. 4, the washing station 100 includes a horizontal arm having one end extending above a rotating table 12.
Including 102. The second end of the arm 102 is relative to the turntable 12 and the capsule 14 mounted thereon.
It is fixed to the elevator mechanism 104 used to lift and lower the vehicle. The elevator mechanism 104 includes, for example, a stepper electric motor that drives a lead screw, the lead screw including a threaded member that is secured to the arm 102 such that when the stepper electric motor is rotated, the threaded member raises and lowers the arm 102. Move to.

An annular seal 106 is fixed to the upper arm 102 of the turntable 12, which annular seal 106 is shown in cross section in FIG. The conduit 108 is fixed to the arm 102
It passes through 102 and is coaxially aligned with the annular seal 106. The lower open end 110 of the conduit 108 is an annular seal 106.
Extends downward from the lower surface of the.

The fluid receiving chamber 112 is coaxially aligned with the conduit 108 below the turntable 12. The upper end of the chamber 112 is open,
Its lower end is narrowed and connected to a conduit 114 which directs waste fluid into a suitable container (not shown).

As seen in FIGS. 1 and 4, conduit 108 is air conduit 1
It is connected to the air pump 118 by 16. Conduit 108 is also connected to a wash solution conduit 120 which is subsequently connected to a wash solution reservoir 122 via a peristaltic pump 124. The conduits 116 and 120 are solenoid controlled valves 126, 1
Includes 28 each. Valve 126 is from the air pump to conduit 108
Valve 128 controls the cleaning solution flowing from pump 124 to conduit 108.

To carry out the washing operation, the swivel table 12 is
So that 14 is coaxially aligned with conduit 108 and chamber 112,
Can be located. With the capsule 14 so aligned, the revoker mechanism 104 is operated to lower the arm 102 so that the annular seal 106 approaches but does not contact the annular flange 26 of the capsule 14. The cleaning solution is then supplied to capsule 14 via conduit 108. The arm 102 is lowered until the wash solution is removed and the filter is returned to its hydrophobic state, as described in more detail below, by operating the elevator mechanism 104 and pressing the annular seal 106 against the flange 26. Air then conduit 108
Is delivered to the capsule 14 through the filter 22 and blows the wash solution through and out of the capsule 14. When the wash cycle is complete, the elevator mechanism 104 is activated and the arm 10
2, thus raising the end 110 above the flange 26. The turntable 12 is then rotated to reposition the capsule 14.

The system 10 further includes a substrate station 130 (FIG. 1) and a read station 132. Liquid substrate from reservoir 134 is directed to precision pump 138 via tube 136.
Precision pump 138 is configured to deliver the correct amount of substrate to substrate station 130 via conduit 140. Substrate station 130 is similar to wash station 100, but is configured to provide only liquid substrate to capsule 14 properly aligned with substrate station 130.

The read station 132 is also similar to the wash station 100, with a horizontal arm 142 extending above the turntable 12.
(Fig. 5) is included. Through the arm 142, a single conduit 144 secured to the arm 142 is coaxially aligned with the annular seal 146. The conduit 144 leads to an air pump 148. A fluid receiving chamber 149 is located below the turntable 12 and the conduit 1
Aligned with 44 and annular seal 146. The fluid receiving chamber 149 is in fluid communication with the fluorometer 150 that includes a cell 152 through which the substrate from the capsule 14 flows. The light source 154 guides light at a predetermined wavelength to the cell 152, and the fluorescence at the second wavelength is filtered by the filter 156.
And is detected by the photodetector 158. Filter 1
56 and photodetector 158 are positioned at an angle of 90 ° from cell 152 with respect to the angle of light from light source 154. The output of photodetector 158 is a circuit 159 well known in the art to provide an output related to the fluorescence of the substrate.
And processed by it. When the fluorescence measurement is made, the pinch valve 160 is opened and the substrate is placed in the cell 152.
To a suitable waste container (not shown). System 10 also includes conventional means (not shown) for cleaning fluid receiving chamber 149 and fluorometer 150 after each use.
Can be included. Further, fluorometer 150 can be replaced by a spectrophotometer configured to measure the absorbance or transmittance of the substrate.

The system 10 includes a microprocessor-based controller 162, as is well known in the art.
(FIG. 1). The controller is configured to be directed by the keyboard 164 and can output data to the display 166 and printer 168. The controller 162 includes a sample transfer subsystem 78, a reagent transfer subsystem 90, a wash, substrate and read subsystem.
Controls the operation of 100, 130, 132, peristaltic and precision pumps 124, 138, air pumps 118, 148, valves 126, 128 and stepper motor 76. The controller 162 also analyzes the fluorescence measurements in response to the output of the circuitry 159,
Such measurements are associated with a standard curve, which determines the concentration of analyte in the sample. All such techniques are well known in the automated clinical analysis arts.

Upon completion of all operations with capsule 14, capsule 14 may be discharged or removed at removal station 170.

The system 10 includes suitable temperature control means to maintain the rotary table 12 at a constant temperature, as well as the capsule 14 disposed on the rotary table 12, as is well known in the art.

The immunoassay to be performed on the system 10 begins with the user selecting a capsule 14 containing the appropriate solid support for the test desired by the user. For example,
The selected capsule 14 may include a solid support adapted for competitive fluorescent enzyme immunoassay for assay T ₃ .
The capsule 14 initially has a seal over the flange 26, which seal is removed by the user. The capsule 14 is placed in the restraint means 60 on the turntable 12.

To control the operation of the system 10, the user selects a particular one of the sample cups 84 with the keyboard 164. A sample is removed from the sample cup and identified in the test to be performed, eg T ₃ . Based on the position of the turntable 12, the controller 162 correlates the loaded capsule 14 at the loading station 61 with the selected sample, tests it, and performs certain procedures as described below. Control the system 10.

Rotating table 12, and thus capsule 14 is a stepper motor 76
And the flexible belt 68 allows the capsule 14 to
It is rotated until it is located at the wash station 100 where the initial wash or prewash operation is performed. Referring to FIG. 4, the arm 102 is lowered until the annular seal 106 does not contact but is near the flange 26 of the capsule 14.
Approximately 0.5 milliliters of wash solution from reservoir 122 is delivered by pump 124 to capsule 14 via valve 128, conduit 120 and conduit 108 heard.

In its initial or hydrophobic state, the hydrophobic nature of the filter 22 causes the filter to repel a wash solution, such as water, thus retaining the wash solution in the reaction chamber 58. In the examples disclosed herein, the wash solution can be a saline solution. The arm 102 is then lowered so that the seal 106 contacts the flange 26 and slightly compresses the flange. Air pump 118 is operated to provide approximately 1.05 kg / cm ² (15 psi) of air to capsule 14 via open valve 126, conduit 116 and conduit 108. The air pressure inside the capsule 14 is filtered
Moisten 22 and flush the wash solution through filter 22 and out of capsule 14. The wash solution enters chamber 112 and flows through conduit 114 to a waste container. Wash solution capsules 1
When emptied from 4, the flow of air through the uniquely selected filter 22 expels liquid from the slits of the filter 22, thus reestablishing the hydrophobic nature of the filter 22.

Upon completion of the prewash, the turntable 12 is rotated to position the capsule 14 at the sample supply station 86. The sample transfer subsystem 78 is operated to withdraw a predetermined amount of the selected sample from one of the sample cups 84 and to supply that sample volume by the probe 82 into the capsule 14 at the sample supply station 86.

The turntable 12 is rotated again to position the capsule 14 at the reagent supply station 98. Reagent transfer subsystem
90 is operated to supply the capsule 14 with a predetermined amount of one or more selected antibody reagents contained in the reagent bottle 97. The hydrophobic state of the filter 22 holds the sample and one or more reagents within the capsule 14. The immunoanalytical effect is then triggered in the capsule 14. And, during the reaction, the contents of the capsule 14 are exposed to the vortex mixing action created by the eccentric cam 66. The eccentric cam 66 is approximately
Has a head of 2.5 mm (0.1 inch), approximately 1250-1700 rp
It is rotated by m and creates a vortex action inside the capsule 14.

When the immunoassay reaction is complete, the capsule 14 turns into a turntable.
It is moved to the washing station 100 by twelve rotations. At wash station 100, the sample and one or more reagents are blown out of capsule 14 and multiple wash cycles are performed. Each wash cycle includes a short vortexing cycle. The air passing through the filter 22 reestablishes the hydrophobic state of the filter 22 as the sample and reagent are blown out of the capsule 14 at the end of each wash cycle.

The capsule 14 is then moved to the substrate station 130 by rotation of the turntable 12. Substrate station 130
The substrate is then added to the capsule 14 from the reservoir 134.
The capsule 14 is stirred again by utilizing the vortex action, and the enzymatic reaction is caused for a predetermined culture period. At the end of the culture period,
The capsule 14 is moved to the reading station 132 and air is added to the capsule 14 from an air pump 148 to expel the substrate from the capsule 14 into a cell 152 where the fluorescence of the substrate is measured. Depending on the fluorescence present in the substrate, the concentration of analyte in the sample can be determined using well known techniques.

Although the example operation described above was described for a single capsule performing a single test, the system 10 performs multiple different tests simultaneously for each capsule 14 mounted on the turntable 12. You can do it. Controller in each case
162 correlates the location of individual capsules 14 on turntable 12 with user-specified samples and tests. The test specifications are used by controller 162 to select the exact reagent or reagents to be directed to each capsule 14. The controller 162 also provides the necessary timing functions for each capsule 14 according to the tests specified. All such control functions are well known and are readily apparent to those of ordinary skill in the art of automated clinical analysis.

Examples of suitable reagents with processing times for competitive and sandwich immunoassays of fluorescent enzymes are as follows:

Competitive FEIA solid support: 50u particles of cellulose with covalently attached goat anti-rabbit gammaglobulin.

Prewash: Wash once with 0.5 ml standard saline, no vortex.

EIA reagent: (1) Specific rabbit antibody; (2) Analytical item complexed with alkaline phosphatase.

EIA incubation time and vortex: Approximately 10-30 minutes (depending on the analytical item), continuous vortexing.

Washing, number of cycles: 0.5 ml of standard saline for 3 washing cycles, vortexing for 3-5 seconds in each cycle.

Substrate: 4-methylumbelliferone phosphate 0.05
mM.

Substrate incubation time and vortex: 37 ° ± 0.2 ° C approximately 5-30 minutes,
Continuous vortex stirring.

Fluorescence analysis method: Light source: 360 nm ± 2 nm, full width at half maximum of 5 nm. Fluorescence: 450
nm ± 10 nm, full width at half maximum of 10 to 20 nm.

Sandwich FEIA solid support: 50u particles of cellulose covalently attached with a univalent (1 °) antibody.

Pre-wash solution and time: same as competitive FEIA.

EIA Reagent: Alkaline phosphatase conjugated to a bivalent antibody.

EIA incubation time and vortex: Approximately 10-60 minutes (depending on assay), continuous vortexing.

Washing, number of cycles: 3-4 washing cycles (depending on the analytical item) with 0.5 ml standard saline, vortexing for 3-5 seconds in each cycle.

Substrate: same as competitive FEIA.

Substrate incubation time and vortex: Same as competitive FEIA.

Fluorescence method: same as competitive FEIA.

Although the above examples show that vortexing is continuous throughout the different incubation times, vortexing during such incubation periods for analyzes processed with a particular capsule 14 It can be interrupted to carry out the actions required for the other capsules 14 on the turntable 12, such as sample, reagent or substrate transfer and wash cycles.

The air pump 118 and peristaltic pump 124 of FIG. 1 can be replaced by a single pump with few moving parts that provides both the wash solution and the air that is blown through the filter 22. Such a pump 178 includes a cylindrical chamber 180 having an open upper end 182, as shown in FIG.
The lower end 184 of the chamber 180 is beveled and is connected to the conduit 186. Conduit 186 includes a one-way valve 188 and conduit 108
(FIG. 4).

The chamber 180 includes two inlets, a first lower inlet 190 and a second upper inlet 192. Lower entrance 190 is conduit 194
And is coupled to the wash solution reservoir 196 via. Conduit 194
Includes a one-way valve 198 that allows flush solution to flow only from reservoir 196 to pump 178.

The upper inlet 192 is provided by the conduit 200, which is simply the filter 20.
Coupled to a suitable air source at atmospheric pressure, which can be 2. Conduit 2
00 also includes a one-way valve 204 that allows air to flow only toward pump 178.

The piston 206 is located within the chamber 180. This piston 206
Is an O-ring 208 between the piston 206 and the inner wall of the chamber 180.
Including a suitable seal such as. The piston 206 can move up and down in the chamber 180 by a rod 210 driven by a stepper electric motor 212 that is sequentially controlled by the controller 162.

In use, the pump cycle will move piston 206 to inlet 19
Start closest to entrance 190 between 0 and 192. The stepper motor 212 is operated to pull the piston 206 upwards within the chamber 180 to draw the wash solution from the reservoir 106 into the conduit 194.
And through valve 198 into chamber 180. The cleaning solution is supplied to the chamber 180 until the piston 206 reaches the upper inlet 192.
Be drawn into. As piston 206 moves above inlet 192, air is passed through filter 202, conduit 200 and valve 204.
It is drawn into the room 180 through. Since the air available in the filter 202 is at atmospheric pressure, any further cleaning solution will:
As the piston continues to move upward in chamber 180, it will not be withdrawn from reservoir 196.

Stepper motor 2 to complete pump 178 cycle
12 is operated to move piston 206 downward within chamber 180. One-way valves 198,204 prevent backflow into conduits 194,200. As a result, the wash solution in the lower portion of pump chamber 180 is first extruded into capsule 14 via conduit 186 and one-way valve 188 and via conduit 108 (FIG. 4). When the wash solution is discharged from the chamber 180, the room air is then forced through the conduit 186 and valve 188 into the capsule 14. As previously mentioned, the air flowing through the filter 22 renders the filter 22 hydrophobic.

Thus, the pump 178 of FIG. 6 will provide both the wash solution and compressed air to the capsule 14 located at the wash station 100, and the air pump 118, the peristaltic pump 1
24 and valves 126, 128 replaced, thereby replacing the first
The system 10 shown is simplified.

Several modifications may be utilized in various aspects of system 10. For example, the air pump 118 is disclosed to create a pressure differential across the filter 22, first of all
Wetting 22 and thereby initiating the flow of liquid therethrough, which then causes the moist liquid to escape from the slits of filter 22 and return to its hydrophobic state of filter 22. However, a vacuum can be drawn through passage 40 to achieve the same result. Also, although the solid support is initially contained within the capsule 14 when the capsule 14 is placed on the turntable 12, the empty capsule 14 may instead be placed on the turntable 12. In such a case, the solid support would be present in the system 10 in the form of a slurry pipetted into the capsule 14 by the reagent delivery subsystem 90. The liquid portion of the slurry will first be blown out of the capsule at the washing station by the application of air pressure, followed by the pre-washing of the solid support described above.

The above detailed description is not to be construed as limiting the scope of the invention which is limited according to the appended claims and all equivalents thereof.

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Claims (9)

[Claims] 1. A reaction capsule for performing an immunoassay, which comprises a tubular member having a first end and a second end, and a porous hydrophobic substance. A film that closes the ends of the film, wherein the substance holds liquid by the film in the tubular member when there is no pressure difference between one side and the other side of the film, The liquid is expelled through the coating by creating a pressure differential between one side and the other side, which causes a flow of liquid through the coating and by flowing a gas through the coating. A reaction capsule having pores sized to stop the flow of the liquid. 2. The reaction capsule according to claim 1, wherein the reaction capsule includes a support rib fixed to the first end, and the film is supported by the support rib. 3. The reaction capsule includes a solid support in which a substance capable of specifically binding to a substance to be measured for immunoassay is immobilized in the cylindrical member.
The reaction capsule according to the item. 4. A tubular member having a first end and a second end, a coating for closing the first end and comprising a porous hydrophobic substance, and the tubular. A reaction capsule comprising a solid support on which a substance capable of specifically binding with a substance to be measured in an immunoassay in a tubular member is immobilized, wherein the hydrophobic substance is one of the films. By holding the liquid by the film in the tubular member when there is no pressure difference between the one side and the other side, and by causing a pressure difference between one side of the film and the other side. A reaction capsule having pores sized such that the liquid is expelled through the coating, thereby causing a flow of the liquid through the coating and stopping the flow of the liquid by flowing a gas through the coating. , The reaction capsule above the coating An immunoassay system comprising: means for directing a liquid to the membrane; means for creating a pressure difference sufficient to cause the fluid to flow through the membrane; and means for flowing a gas through the membrane. 5. The immunoassay system according to claim 4, further comprising: a rotary table that supports a plurality of reagent capsules; and an eccentric means that displaces the rotary table to create a vortex action in the reagent capsules. . 6. The means for directing the liquid and the means for flowing the gas include a pump, the pump being a cylinder having a lower end and an upper end, the lower end being closed. And a cylinder formed to be in fluid connection with the reaction capsule, a lower liquid inlet and an upper gas inlet, a piston movable in the cylinder, and the piston displaced by a stroke including the upper gas inlet. The immunoassay system according to claim 4, further comprising: 7. A patient sample, a solid support on which a substance capable of specifically binding to a substance to be measured in the sample is immobilized, and a labeled substance at the lower end. Adding to a reaction capsule having a hydrophobic coating, causing an immunoassay reaction, exerting a pressure difference on the reaction capsule to cause a flow of liquid through the coating, coating the coating to stop the flow of liquid Flowing a gas through the cell, and measuring the result of the immunoassay reaction. 8. Introducing a cleaning solution into the reaction capsule when the coating is in a fluid-free state, wherein one side of the coating and the other side of the coating form a flow of cleaning solution through the coating. The immunoassay method according to claim 7, which comprises creating a pressure difference therebetween and flowing a gas through the film to stop the flow of the cleaning solution. 9. Adding a liquid substrate to the reaction capsule, causing a reaction to create a predetermined substance within the reaction capsule, the film to cause a flow of the liquid substrate and the substance through the film. Creating a pressure differential between one side and the other, collecting the liquid substrate and substance in a cell, measuring the amount of the substance in the cell to determine the quality of the patient sample The immunoassay method according to claim 8, which comprises: