FI91808B - Immunological determination system - Google Patents

Description

1 91808

Immunological assay system

The invention relates to an automated immunoassay system using the inner surface of a reaction vessel as a solid phase. The system of the invention can be used in general for photometric, fluorometric, phosphorimetric or radiological immunoassays.

To determine the antibody (or antigen) in a sample, the so-called heterogeneous immunoassay methods in which an antibody (or antigen, respectively) and a labeled antibody (or antigen, respectively) are allowed to bind to an antigen (or antibody, respectively) placed on a solid surface. These methods have a solid surface on which the immunological reaction has taken place, and the reaction solution is separated from the solid surface before measuring the tracer signal so that the excess tracer in the reaction solution does not mask the signal in the solid phase-bound antibody (or antigen, respectively). This signal may be, for example, radioactivity (RIA), fluoro-. 20 reactive activity (FIA) or enzyme activity (EIA).

In all these methods, the solid phase must be washed thoroughly before measurement.

The methods currently in use always have manual steps; at least a washing step for which no reliable means of practically reliable operation have been found.

Automated methods must aim to use reaction and measurement cuvettes made up of several sample vessels. The reactions must generally be carried out at a predetermined temperature. To control the temperature, in-incubators have been used with a heated body and a separate cuvette-shaped cavity for each cuvette in the cuvette.

However, this solution is not satisfactory, since it is so difficult to keep the temperatures of the various cuvettes sufficiently accurate. In this way, it is not possible to use cuvettes as large as would be advantageous from the point of view of automation.

It is a primary object of the present invention to provide a fully automated heterogeneous immunoassay system. In particular, the aim is to provide a system in which the heating and washing steps also take place automatically and reliably, even when using large cuvettes.

The present invention includes: a horizontally movable cuvette carriage; a horizontally movable dispensing head above it; a single-ended liquid dispenser attached to the dispensing head and having a tip that is lowerable to the bottom of the cuvette below; a dispensing apparatus for introducing the desired liquid into the cuvette and removing the solution 10 in the cuvette from the cuvette through the tip; and a measuring device attached to the dosing head. The invention and some of its applications are precisely defined in the claims.

A preferred embodiment of the invention is illustrated in more detail by means of the accompanying drawings. In them, Fig. 1 15 shows an overall view of the system, Fig. 2 a partial view inside the analyzer, Fig. 3 the tip of a liquid dispenser lowered to the bottom of the cuvette and Fig. 4 a thermostated incubator of the apparatus.

The main components of the equipment are the analyzer 1, the computer 2 20 with its display terminals 3 and the printer 4. Other control or data transmission and storage devices 5 can also be connected to the system. The analyzer also has its own operation and output panel 6. The analyzer cover 7 opens. The sample cuvette is placed in the moving carriage 8. The trajectory of the carriage is 25 straight lines and marked with an arrow at the end of the carriage. Above the carriage 8 there is a dosing head 9 movable along a path perpendicular to the trajectory of the carriage, to which a photometer 10 and a liquid dispenser 11 are attached. The direction of movement of the dosing head 9 is indicated by an arrow 30a next to it.

The measurement is performed by passing a light beam from below the hole 12 through the bottom of the sample cuvette through the measuring tip 13 of the photometer 10 for detection.

The liquid dispenser 11 has a main channel 14 connected to the pump 1 and a side channel 15 connected to the piston pump opening therein (Fig. 3). The tip 15 of the liquid dispenser can be lowered to the bottom of the cuvette below.

The tip 15 of the liquid dispenser 11 is made of a flexible material and is preferably curved (Figure 3). When the curved tip 15 is lowered to the bottom of the cuvette 18 of the cassette 17, the tip mouth settles in the corner of the cuvette 18. In this way, the liquid in the cuvette 18 is absorbed as completely as possible.

The analyzer uses a vertical measuring cuvette 17, 5 with a plurality of cylindrical measuring cuvettes 18 with a transparent base, which are connected at the top to each other into a rectangular matrix on a support plate. The antigen of the antibody to be determined is pre-attached to the inner walls, in particular the bottoms, of the Ky waters 18. The carriage 8 10 has light transmitting holes at the cuvettes 18.

Carriage 8 has a thermostated incubator in which the cuvette is placed. The incubator has heating pins located between the cuvettes 18. The pins 19 are square in cross-section, the sides of which curve inwards along the walls of the cuvettes 18 15 so that a small gap is left between the pins 19 and the cuvettes (Fig. 4). This allows air to circulate freely between the cuvettes, keeping the temperature of all cuvettes as close as possible to desired.

The carriage 8 has a space 20 for the cuvette system 17 as well as a space 21 20 for the sample vessels and a place 22 for the necessary reagent and liquid removal vessels.

The hardware works as follows:

The lid 7 of the analyzer is opened and the samples, for example serum samples, are placed in the space 21 reserved for them and the cuvette 17 in the space 20 reserved for it. The lid 7 is closed and the desired program is started. The liquid dispenser 11 picks up and dilutes each sample in its own cuvette 18 and picks up and dispenses the labeled antibody and other reagents as needed into each cuvette. Samples 30 are incubated for the desired time at which the immunological reaction occurs.

Now, the liquid dispenser 11 alternately draws the reaction solutions of all the cuvettes 18 into the main channel 14 and removes them into the container provided for them, while rinsing the channel. Now, all cuvettes are dispensed alternately with washing liquid 14 from the main channel, after which the cuvettes are again emptied as described above. Finally, the amount of labeled antibody bound to each cuvette is measured and the results of the assay are printed as desired.

The solution is removed from the cuvette by inserting the tip 15 into the bottom of the cuvette 18 and, when the solution is sucked out, moving the curved tip 15 against the corner of the cuvette. In this way, the tip 15 5 is always accurately placed in the corner of the cuvette 18 and the solution removed as accurately as possible.

The wash liquid is dispensed into the cuvette 18 so that the liquid jet does not detach without reacting with the antibody, but nevertheless removes excess labeled antibody and other impurities from the solution.

A preferred photometric application has been described above. The arrangement can also be applied to fluorometric or radiological measurement. Otherwise, the hardware may differ in detail from the above. It may have, for example, a separate incubation station to which the trolley is driven. The dosing head can, of course, also be used during incubation, as can a photometer.

In a preferred embodiment, several different assay sequences are performed simultaneously.

Claims (8)

An immunological determination device comprising a carriage (8) movable in the horizontal plane having a space (20) for a cuvette system (17), a dosing device (9) movable in the horizontal plane above the carriage (8), a liquid dispenser (11) having a tip attached to the metering end (9) and the tip (15) of which can be lowered into the bottom of a cuvette (18) on its lower side, 10. a metering device for delivering liquid to the cuvette and to remove a solution from the cuvette through the tip (15), a measuring device (10) fixed to the metering end (9) and intended to measure a signal, characterized in that the cuvette space (20) in the carriage (8) ) is a heated incubator, the cuvettes (18) of the cuvette system on its inside have an antigen attached to the subject to be determined, and the measuring device is intended to measure a signal emitted by a marking substance attached to the inner wall of the cuvette (18). . Device according to claim 1, characterized in that the carriage is movable only along a rectilinear path. Device according to claim 1, characterized in that the dosing end is movable only along a rectilinear path. Device according to any of claims 1-4, characterized in that the carriage has a space (20) for a cuvette system (17), whose cuvettes (18) form a rectangular matrix and are fixed to each other from their upper ends. with a support plate and where there are heating pins (19) in the incubator which are placed in the spaces between the cuvettes. Device according to claim 4, characterized in that the cross-section of the heating pins (19) is substantially square. Device according to claim 5, characterized in that. where the carriage has a space (20) for a cuvette system (17), the cuvettes of which are cylindrical and where the side walls of the heating pins (19) are concave to correspond to the curvature of the walls of the cuvettes. Device according to any one of claims 1-6, characterized in that the tip (15) of the liquid dispenser (11) is curved. 5 8. A method for determining a counterpart in a liquid sample, in which a method of placing a cuvette system (17) in a carriage movable in the horizontal plane (17), allows the immunological reaction to take place, 10. by means of a measuring device ( 10) which is fixed at the metering end (9) measures a signal emitted by a labeling blank, characterized in that the cuvettes (18) of the cuvette system (17) have an antigen for the counterpart to be determined, - in a thermoregulable cart (8) places sample vessels containing the samples to be determined, and reagent vessels containing the necessary reagents, by means of a liquid dispenser (11) having a tip (15) moving above the cart (8), where the tip (15) can be lowered into the bottom of a cuvette (18) pk its lower side, fetching into each cuvette a sample from the sample vessel and reagents from the reagent vessels. by means of the tip (15), the solutions remove from the cuvettes (18), by means of the tip (15) dispense detergent to the cuvettes and remove them from them, and measure as a marking substance which sticks to the inner wall of the cuvette (18). li