HK1070315B - A multi-compartment reagent container having means to inhibit re-use thereof - Google Patents

Description

Multi-compartment reagent container with means to prevent reuse

Technical Field

The present invention relates to a method and a device for automatically treating a patient with biological fluids such as urine, serum, plasma, cerebrospinal fluid and the like. In particular, the present invention provides a method of preventing accidental reuse of reagents contained in reagent containers that have been previously used.

Background

Various tests for diagnosis and treatment of patients can be performed by analyzing analytes in infection, body fluid, or abscess samples of patients. Combining a patient's sample with various assay reagents in a reaction vessel; the mixture is then incubated and analyzed using interrogating (interventional) radiation measurements to assist in patient treatment. Automated clinical analyzers for chemical, immunochemical, and biological testing of such sample-reagent mixtures are known, and typically add one or two assay reagents to a liquid sample, the reagents being obtained from a reagent storage compartment held on the analyzer.

For an automated chemical analyzer to be convenient and compact, it is desirable to store all of the reagents required to perform a single assay in successive compartments or vessels. This type of vessel is a multi-compartment reagent vessel that can be used in an Analyzer known as Dimension  Chemical Analyzer, sold by Dade Behring Inc, Deerfield, IL. The multi-Compartment Container is in the form of a Container strip as described in U.S. patent No.4720374 entitled "Container Having a sound company" to Ramachandran and includes a rigid circumferential band formed of an inert resin. The strip is integrated with the respective reagent container such that the container strip tapers in a substantially elongated wedge-like manner from a first edge towards a second edge. This wedge-shaped planar shape of the container strips facilitates mounting of a large number of such test strips in circumferentially adjacent and substantially radially extending relationship on the rotatable reagent carrier plate as described in U.S. Pat. No.4863693 entitled "Analysis Instrument coming A flow Mobile reaction Chamber" of U.S. Pat. No.4863693 to Howell which has a reagent supply arrangement with a row of multi-compartment reagent containers arranged in a substantially radial direction from the vertical center of rotation of the rotating plate. The reagent dry foot source includes a reagent dispensing probe movable in a substantially radially inward or radially outward direction relative to the plate to aspirate a selected reagent from any one of the segmented reagent compartments of the multi-compartment reagent vessel and deposit a predetermined amount of the reagent in one or more reaction vessels disposed at an angular position around the circumference of the plate.

The top of the multi-compartment reagent vessel may be sealed by a suitable laminate that prevents escape of gas and vapour, yet allows for the passage of probes for suction etc. The plastic for the receiver is polyethylene and the laminate is a three layer laminate of a polyester film, a polyvinylidene chloride coating on the polyester film, and a final polyethylene sheet adhered to the coating. The laminate is heat sealed to the peripheral surface of the polyethylene compartment by contacting the bottom polyethylene sheet with the compartment rim. Variations of the multi-compartment reagent vessel are described in U.S. patent nos. 4935274 and 5009942, which are assigned to the assignee of the present invention.

A problem that has been experienced with the use of reagent containers for use on automated clinical analyzers is the accidental attempt to reuse reagent containers that have been used on the analyzer before. When the container is used on an analyser, a portion of the reagent is removed by the reagent aspiration device; when the container is removed from the analyzer, the amount of reagent remaining in the container may be contaminated or stored in a hazardous environment, and thus, their reaction characteristics will change. In this case, an erroneous analysis result may be derived by the analyzer before the situation is noticed and corrected. Accordingly, even when a reagent container is first placed on the analyzer, it is desirable to provide an automated method of determining whether the container is new and unused, or whether the container has been previously used.

U.S. patent No.5976469 discloses an analysis sample cup having a removable type lid to define a test space in which a chemical strip is mounted; the cup includes a selectively removable protective cover for selectively covering and uncovering the outer surface of the transparent portion of the outer partition forming the test space. The protective cover is formed as one piece with the inner partition for mounting on the inner partition by a double living hinge. The cover is rectangular in shape and includes an elongated magnifying lens having a protrusion extending into the blind hole of the inner partition. The magnifying lens extends across the transparent portion of the outer barrier. When the protective cover is in the closed position, it hits the magnifying lens.

U.S. patent No.5645824 discloses a color changing reagent composition for application to a syringe needle or other needle containing a medical device that upon contact with bodily fluids such as blood, mucus, saliva and semen, causes the composition applied to the needle to change color to signal prior use and contamination of the potentially infected bodily fluid.

Us patent No.5472415 discloses an instrument for assessing the suitability of a corresponding orthopedic implant. The instrument will be designed as a disposable single use temporary instrument component. The temporary instrument component is made of a material that is sterilizable by gamma radiation, but it provides a visual indicator, such as a visual deformation, when resterilized by exposure to a heated environment, thereby preventing or preventing reuse of the component.

U.S. patent No.5403551 discloses an assay device for collecting and analyzing a sample that includes a receptacle and an opening for collecting the sample in a chamber that stores the sample. A cap is used to seal the container opening and at least one assay system is mounted on the container for performing chemical analysis on the sample. Channels are also provided to enable a portion of the sample to enter the assay system by changing the orientation of the container. Tamper-resistant devices are provided through the use of a releasable seal that allows a test sample to enter the assay system only when appropriate.

Us patent No.5255804 discloses a tamper-evident closure for a tube, comprising a neck projection at the neck of the tube which is riveted to the edge of a sleeve portion in a cap. After breaking the neck protrusion to use the tube, the cap can be replaced on the tube, but the connection is loose, so that when the tube is picked up again, the cap immediately falls off the neck, indicating that it has been used previously.

Us patent No.4591062 discloses a tamper evident closure arrangement for an internally pressurised container, comprising a closure having means for venting internally pressurised gas by first unsealing the container and tamper indicating means for acting with the vented gas to indicate that the container has been first unsealed. The tamper indicating means may for example be chemically activated to change colour when acted upon by the evolved gas, or may be mechanically activated such that the evolution of pressurised gas results in a visibly apparent rupture, flexing or the like to indicate the first unsealing of the container.

U.S. patent No.4286640 discloses a tamper-evident cap for a port of a medical fluid container that, when applied to the port, will indicate that additive material has been introduced into the container. The lid of the port is molded of a resinous plastic material and includes a latch portion that is inserted into a locking bar that serves as a means of preventing access to the latch portion, thereby forming a tamper-evident structure. The latch portion is of barbed cross-sectional shape and guided by the inclined ramp into the locking notch, which creates a press fit, so that after the barbed portion is forced through the locking notch, the barbed portion will expand to engage the locking surface in the locking lever.

By way of introduction to the state of the art for automated clinical analyzers, it has been found that while there has been an improvement in containers that are clearly indicative of tampering, there has been no improvement in reducing the potential problems caused by the reuse of clinical assay reagent containers. Therefore, there is also a need for a method and a reagent container that will not be used when a reagent container that has been used before is used in an analyzer, and/or that warns an operator that the result obtained by the analyzer is obtained by using a reagent container that has been used before, and therefore the assay result is questionable.

Disclosure of Invention

It is a primary object of the present invention to provide a method for automatically determining whether a reagent container is new and unused or whether the reagent container has been previously used when the reagent container is first placed on an analyzer.

To this end, the present invention provides a method for determining whether a reagent container having at least one end wall has been previously used when said reagent container is placed on an analyser, the method comprising: providing an unused container having a weakened bridge member mounted on said at least one end wall, the weakened bridge member including a bridge member weakened at a central region thereof and supported between two brackets extending outwardly from said end wall, the bridge member and the brackets defining an open area adjacent said end wall; moving the weakened bridge by a sensor probe for signaling movement of the weakened bridge when the unused container is placed on an analyzer; and analysing the signal to determine whether the signal value falls outside a predetermined range of signal values representing a container that has not been used before.

In a first exemplary embodiment of the present invention, when a reagent container is placed on a clinical analyzer, a movable sensor probe within the analyzer determines the presence or absence of a locking feature mounted on the reagent container. Furthermore, when neither the probe's run length nor the moving force falls within a predetermined range, an attempt may be made to override (over-ride) the locking feature. In this embodiment, the locking member may be forcibly removed from the container by the probe.

The present invention also provides a multi-compartment reagent container in the form of a container strip tapering in an elongated wedge shape between two side walls from a first end wall toward a second end wall, the container having a weakened bridge mounted on at least one end wall, the weakened bridge comprising a member weakened in a central region thereof and supported between two brackets extending outwardly from the end wall, the bridge and the brackets defining an open area adjacent the end wall.

In an alternative embodiment of the invention, the locking member is a "two position snap" design in which the selectively weakened bridge member is moved or transitioned from an original "new" position to a "used" position when the container is first placed on the analyzer. In this embodiment, the bridge member is held as a permanent but movable part of the reagent container. In embodiments of the invention, the analyzer may be programmed to automatically eject reagent containers that have been previously used; alternatively, the analyzer may continue the analysis of the sample without discontinuing the analysis of the reagent in the container that has been previously used, but automatically prompting the reuse in the read analysis results.

Drawings

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which form a part hereof, and wherein:

FIG. 1 is a schematic plan view of a reagent container having features necessary to implement embodiments of the locking features of the present invention;

FIG. 2 is an isometric view of the reagent vessel of FIG. 1 showing an alternative locking embodiment of the present invention;

FIG. 2A is an isometric view of the alternative locking embodiment of FIG. 2, showing the use of a sensor probe to rupture a labeled portion of the reagent container of FIG. 1;

FIG. 3 is a graph showing signals generally generated by the sensor probe of FIG. 2A when practicing the present invention;

FIG. 4 is an enlarged view of an example locking member of the reagent container of FIG. 1 in an unused state;

FIG. 5 is an isometric view of the locking member of FIG. 4 in an unused condition;

FIG. 6 is an enlarged view of an exemplary locking member of the reagent container of FIG. 1 in a post-use state;

FIG. 7 is a schematic front view of the reagent vessel of FIG. 1 illustrating an embodiment of the present invention employing the locking member of FIG. 4;

FIG. 8 is a schematic plan view showing the embodiment of FIG. 7, employing the locking member of FIG. 4; and

FIG. 9 is a graph of sensor signals generated when implementing the embodiment of FIG. 7.

Detailed Description

Fig. 1 schematically illustrates elements of a multi-compartment reagent vessel 10, together with fig. 2, the multi-compartment reagent vessel 10 including a plurality of compartments 14, the compartments 14 being arranged in end-to-end relationship to form a substantially closed vessel strip between two side walls 12 and depending downwardly from a top surface 15. The reagent vessel 10 may be manufactured in any convenient manner and may be formed from a suitable material, such as an inert plastic. The top surface 15 is connected to each compartment 14, preferably integrally formed, such that the reagent vessel 10 tapers in a substantially elongated wedge-like manner from a first wider edge wall 18 towards a second narrower edge wall 16. This wedge-shaped planar shape of the containers 10 facilitates mounting a large number of such reagent containers 10 in circumferentially adjacent and substantially radially extending relationship on a rotatable reagent carrier plate (U.S. patent No. 4863693). It is understood, however, that the containers may be of any predetermined configuration and may be used individually or arranged together in any suitable number while remaining within the contemplation of the present invention.

As described in the aforementioned U.S. patent No.4720374, reagent container 10 is a commercial FLEX (tm) cassette sold by Dade Behring Inc, Deerfield, IL and contains the reagents required to perform a particular assay. Each compartment 14 is typically in the form of a closed well defined by a plurality of substantially opposed pairs of substantially parallel and integral side and end walls. The upper surfaces of the side and end walls are aligned with the upper surface 15 of the reagent vessel 10 in its vicinity to define a substantially planar sealing surface around the open upper end of the compartment 14. Each compartment 14 is closed by a downwardly sloping floor. The top surface 15 of the multi-compartment reagent vessel 10 may be sealed by a suitable laminate (not shown) that prevents escape of gas and vapor, and also allows for the passage of probes for aspiration and the like.

The main object of the present invention is to provide a method for automatically judging whether a reagent vessel 10 is new and unused when the reagent vessel 10 is first placed on an analyzer, or whether the reagent vessel 10 has been used previously. The terms "new" and "unused" are meant to convey a condition that has not previously been placed within the analyzer, regardless of whether reagent has been withdrawn from compartment 14. In the first embodiment of the present invention, the reagent vessel 10 is provided with the perforation flag member 21 (fig. 2 and 2A), and the perforation flag member 21 is in the shape of a rectangular thin plate in the lowest portion of each side wall 12. Preferably, the flag member 21 is formed during molding of the container 10 and is of the same material as the container 10, but is only attached to the side wall 12 along the weakened top flag edge 23 (shown in phantom) and is not attached to the side wall 12 along both side wall edges 25 of the flag member 21. Obvious equivalents of the flag member 21 include a side wall, end wall, top or bottom flag-like portion that has a circular, oblong, and the like shape and that is half-mounted on the container 10. When the container 10 is placed on the analyser, the active sensor probe 27 within the analyser is automatically extended into contact with the label member 21 by a suitable actuator. Sensor probe 27 includes a conventional pressure sensing transducer and displacement transducer for providing electronic signals indicative of the resistance encountered by probe 27 and the length of travel of sensor probe 27. Such probes are well known in the art and are available from companies such as Schaevitz engineering, Hampton Virginia. When in contact with the marking member 21, the sensor probe 27 generates a non-zero resistance signal, as indicated by the letter "C" corresponding to position #1 in FIG. 3, at which position the probe 27 comes into physical contact with the container 10. Continued movement of the sensor probe 27 into the body of the container 10 (corresponding to position #2 in fig. 3) causes the marking member 21 to flex inwardly from the side wall 12 along the weakened marking edge 23 with increased resistance, as indicated by the letter "B" in fig. 3. Continued movement of the sensor probe 27 into the body of the container 10 will cause the weakened marking edge 23 to rupture and cause the marking member 21 to break away from the side wall 12, as indicated by the letter "S" corresponding to position #3 in fig. 3. The pushing force of the signaling probe 27 can be well adjusted by the skilled person in view of the strength of the connection of the weakened marking edge 23 in order to obtain a stretching and breaking force for relatively brittle construction materials. Alternatively, in embodiments where the container 10 is constructed of a less brittle and more flexible material, the marking members 21 may be flexed inwardly and not removed from the container 10. This allows the marking member 21 to flex outwardly again to near its initial position and the signal generated by the probe 27 may not be very reliable.

It is also known in the art to equip the analyzer with a computer control program that monitors the shape of the signal curve generated by the sensor probe 27 in order to confirm that the reagent vessel 10 is new and unused, based on the length of travel of the probe 27, as well as the force of movement of the probe 27 and the elastic force of the marking member 21. In particular, when the probe 27 indicates no resistance when moving between probe positions #1 and #2, it can be concluded that the container 10 has been used previously because the marking member 21 has been moved away from its initial position in a plane coincident with the side wall 12 of the container. In this case, the container in the analyzer is not in a "new, unused" state, and the quality of the reagent contained in the container cannot be guaranteed. A key feature of the present invention is that when the container 10 is first placed on the analyzer, if the run length and the moving force of the probe 27 do not fall within the previously predetermined ranges (e.g., within the range indicated by the dashed line R in fig. 3 representing about 15% to 20% of the relative value), it can be automatically determined that the reagent container has been previously used. At this point, the analyzer may choose to push out the previously used container, enter a wait state, and signal the operator, or complete the desired test assay, and provide a warning signal regarding the quality of the assay result. In contrast, when the running length and the moving force of the probe 27 fall within predetermined ranges (for example, within a range indicated by a broken line R representing about 15% to 20% of the relative value in fig. 3), it is possible to automatically judge that the reagent vessel has not been used previously. At this point, the analyzer may choose to complete the desired test assay and provide a signal or report indicating that an assay was performed on the reagent in the new container 10.

In this first embodiment, the marking member 21 is typically removed from the container 10 by the sensor probe 27 and may therefore interfere with the automatic operation of the analyzer. The marking member 21 may be formed of a material such as paper, thin plastic or cloth, and is mounted on the container 10 on all boundaries and may be easily penetrated by a movable sensor probe. In this embodiment, the marking member 21 will be pulled inwardly by the sensor probe 27 before breaking. A signal similar to that shown in figure 3 will also be obtained.

In another exemplary embodiment of the present invention, the locking member 17 of the present invention contemplates a "two-position snap" design, wherein a selectively weakened bridge member 24 integral with the reagent container 10 is snap-moved or shifted from an original "new" position to a "used" position. In this embodiment, the bridge member 24 is held on the container 10 as a permanent but removable part of the reagent container 10. Fig. 4 shows a locking element 17, which locking element 17 comprises a weakened bridge element 24, which bridge element 24 is supported between two brackets 22 projecting outwardly from the edge wall 18. Importantly, the bridge member 24 is weakened at its central region by the recess 28 being formed continuously with the open region 30, and the bridge member 24 is weakened at its ends by the narrowing tip at the junction of the bridge member 24 and the bracket 22. The spikes 26 are formed on either side of the bridge member 24 in the recesses 28 to facilitate "breaking" the bridge member 24 from its "initial, unused" position to an inwardly displaced position indicating a "previously used" condition, as shown in figure 6 and described in the following explanation. The degree to which the bridge member 24 is individually weakened by the peaks 26 and troughs 28, respectively, can be adjusted so that movement of the bridge member 24 from the new, unused condition of fig. 4 to the used condition of fig. 6 is permanent. Thus, the bridge member 24 "transitions" from the unused state in fig. 4 to the used state in fig. 6. An open area 30 is also formed between the bridge member 24, the bracket 22 and the edge wall 18 to further accommodate this conversion of the bridge member 24. Figure 5 is a perspective view of the bridge member 24 in an initial "new" position.

As will be described later, in carrying out the method of the present invention, in the embodiment illustrated by figures 4 and 5, when a "new, unused" container 10 is mounted on the analyser, the container 10 is automatically pushed by the motorised transducer against the moving probe and the bridging member 24 is permanently moved to the "broken" position as illustrated in figure 6. The method of moving the bridge member 24 to the "broken" position may vary; however, typically the position and/or the displacement force of the probe and/or the displacement of only the movable probe can be monitored and need to be within a certain predetermined range. The foregoing example shown in fig. 3 is to monitor the force of movement of the sensor as a function of the relative displacement of the sensor in order to determine the used or new status of any reagent container.

In an alternative example method of carrying out the invention, as shown in fig. 7, using a container 10 with the locking means 17 of fig. 4-6, when the container 10 is first inserted into the analyser (stage a, upper part of fig. 7), the container is pushed to the right by a conventional switch (not shown) so that the locking means 17 is moved in the direction of arrow 32 (from left to right) into contact with the active sensor probe 20 (stage B). In this embodiment, the sensor probe is in the form of a displacement probe 20 fitted with a conventional displacement transducer 38 and pressed against a stop 37 so as to be vertically oriented by a biasing spring 36. The container 10 continues to move to the right (stage C) as shown until the probe 20 engages the stationary stop 34 (stage D) and presses against the locking member 17 in the vicinity of the recess 28 (stage D, see fig. 8). The container 10 continues to move to the right by the translator until the stationary stop 34 (stage E) limits further movement of the displacement probe 20, which causes the weakened bridge member 24 of the locking means 17 to break into a broken condition as shown in figure 6. As previously described, the tip 26 and recess 28 are provided to facilitate breaking the bridge member 24 to a permanent inwardly displaced position so that it can be confirmed that the container 10 has been previously placed on the analyzer and is therefore in a "previously used" condition.

At this time, the amount of displacement of the displacement probe 20 with respect to the running length of the container 10 can be analyzed as shown in fig. 9 to determine whether the container 10 has been used previously. This analysis evaluates the displacement of the probe 20 at stage C-when the container 10 has been previously used, the bridging member 24 will be in a broken condition, as shown in figure 6, and the predetermined distance that the probe 20 moves is less than the length of travel of the probe 20 when the bridging member 24 is in an unbroken condition (representing an unused container, as shown in figure 4). Also, when the container 10 has been previously used and the bridging member is in a broken condition, the container 10 must be moved to the right a greater distance in order to achieve the same displacement of the probe 20 (as if the bridging member 24 were in an unbroken condition as shown in figure 4, indicating an unused container).

In fact, for an unused container 10 at stage B, the container 10 has been moved a predetermined distance into the analyzer and brought into contact with the displacement probe 20. Once the container 10 has moved to the right beyond phase B, as shown in phase C, the sensor 38 of the displacement probe 20 must begin to send a signal indicative of the movement, otherwise it can be determined that the container 10 has been previously used and the analyzer can optionally be programmed to reject the used container 10. When the container 10 is first placed on the analyser, the purpose of continued movement of the container 10 beyond stage B is to cause the bridging member 28 to shift to the "used" position as shown in figure 6. Preferably, the condition of the container is also fully analysed in order to detect any undue effort trying to override the effect of the locking member 17, such as the use of adhesive tape to patch a broken bridge member 24 of a container 10 that has been previously used.

The lowermost portion of fig. 7 shows the reverse interaction that occurs when the container 10 is moved to the left (right to left) as indicated by arrow 33 to an operative position within the analyser, after it has been determined by use of the present invention that the container 10 is new and unused or has been previously used. Stage E is repeated for illustration only. At stage F, the container 10 is moved to a position equivalent to stage D, sufficient to cause the probe 20 to begin to clear the stationary stop 34. The container 10 continues to move to the left through stages G-H-J until the container 10 clears the stop 34 and the probe 20 is held in its original vertical orientation by the biasing spring 36.

Fig. 8 is a schematic plan view corresponding to stages a-J of fig. 7 in order to more clearly explain this embodiment of the invention. It can be seen that the weakened bridging member 24 first comes into contact with the probe 20 at stage B, continues to move to the right at stage C, and the probe 20 moves to abut the stationary stop 34 at stage D. Arrows 32 and 33 again represent movement from right to left and left to right, respectively, for purposes of illustration and description only. It is clear that all that is required for carrying out the method of the invention is to move the containers 10 relative to each other. In stage E, the weakened bridging member 24 is shown broken from the unused condition to the used condition by continued movement of the container 10 to press the locking member 17 further against the stop 34. When it 10 is moved to the left to an operative position within the analyser, starting at stage F at the bottom of figure 8, the biasing action of the spring 36 pulls the displacement probe 20 against the now broken bridge member 24. Thus, when and only when a reasonable breaking action of the weakened bridge member 24 occurs, the bridge member 24 will have a displacement difference in stages G and C, indicated by the vertical dash-dotted line in fig. 8. There is a similar difference in displacement between stages D and F. That is, when the container 10 is in the same position at stages C and G or D and F, the displacement probe 20 will have a predetermined difference in the vertical direction, indicated by the letter "P".

FIG. 9 shows signals generated by sensor 38 similar to those used in practicing embodiments of the present invention. The solid line "R" represents the signal received by the sensor 38 during the rightward relative movement of the container 10, and the dashed line "L" represents the signal received by the sensor 38 during the leftward relative movement of the container 10. The first contact between the locking member 17 and the probe 20 occurs at stage B in fig. 8 and 9; in stage C of fig. 8 and 9, the container 10 continues to move to the right, the probe 20 moves to the right, and the sensor probe 38 generates an increasing displacement signal, as shown in stages C and D of fig. 8 and 9. In stage D, the container continues to move to the right by the shuttle mechanism (not shown), causing the probe 20 to cause the weakened bridge member 28 to break or transition from its initial new state to a used state, as shown in stage E of figure 8 and as shown by the letter "S" before stage E in figure 9. As previously mentioned, a key feature of the present invention is that when the container 10 is first placed on the analyzer, it is possible to automatically determine whether the reagent container is new and unused, or whether the reagent container has been previously used, if the signal output by the sensor 38, which is indicative of the displacement of the probe 20 as a function of the position of the container 10, does not fall within the aforementioned predetermined range (e.g. within a range of about 15% to 20% of the relative displacement signal value represented in fig. 9). This range is indicated by a dashed line Ra in fig. 9. As a fail-safe confirmation mechanism, for displacement signals generated by the sensor 38 when the container position corresponds to phases C and G or D and F, the displacement probe 20 will measure a predetermined displacement difference by the sensor 38, which is also indicated by the letter "P" at phases C and G in fig. 9.

In practicing various embodiments of the present invention, the analyzer may be programmed to automatically eject a previously used container, shut down, or allow continued analysis of a sample for a design in a previously used container, but automatically prompt reuse of the container in the presentation of an analysis report. The skill required to have the analyzer automatically perform this action is also within the scope of current computer programs.

Accommodating the various possible designs of the locking member 17 in the container is a commonly encountered consideration in the art and need not be described herein. It is sufficient in the teaching of the present invention that it is possible to determine whether a reagent container has been used before by examining the physical characteristics of the container when it is first placed in the analyser, without the need to set forth equivalent variations which would be apparent to the skilled person. It is therefore to be understood that the embodiments of the invention herein described are illustrative of the principles of the invention and that other variations may be employed within the scope of the invention. For example, the marker member 21 may be of various physical shapes, the locking member 17 may be disposed at various locations on the container 10, and the bridging member 24 may be sufficiently frangible in the broken state. Accordingly, the present invention is not limited to the embodiments shown and described in the specification, but is defined by the following claims.

Claims (13)

1. A method for determining whether a reagent container having at least one end wall has been previously used when the reagent container is placed on an analyzer, the method comprising:

providing an unused container having a weakened bridge member mounted on said at least one end wall, the weakened bridge member including a bridge member weakened at a central region thereof and supported between two brackets extending outwardly from said end wall, the bridge member and the brackets defining an open area adjacent said end wall;

moving the weakened bridge by a sensor probe for signaling movement of the weakened bridge when the unused container is placed on an analyzer; and

the signal is analyzed to determine if the signal value falls outside a predetermined range of signal values representing a container that has not been previously used.

2. The method of claim 1, further comprising: causing the analyzer to automatically push out the container when the signal value falls outside a predetermined range of signal values representing that the container has not been previously used.

3. The method of claim 1, further comprising: the analyzer is automatically caused to issue a warning when the signal value falls outside a predetermined range of signal values representing that the container has not been used before.

4. The method of claim 1, further comprising: the analyzer is automatically put into a waiting mode of operation when said signal value falls outside a predetermined range of signal values representing a container not previously used.

5. The method of claim 1, wherein: the sensor probe includes a displacement readout transducer for providing an electronic signal indicative of the displacement performed by the probe when the probe is brought into contact with the weakened bridge.

6. The method of claim 5, wherein: the bridge is repositioned from an unused position between the brackets to a used position between the brackets by moving the container relative to the sensor probe.

7. The method of claim 1, wherein: the weakened bridge includes a recess formed near a middle portion of the bridge adjacent to the open area.

8. The method of claim 1, wherein: the weakened bridge also includes a pair of prongs formed at the ends of the bridge that connect to the brackets.

9. The method of claim 8, wherein: the tip is formed on a side of the bridge opposite the recess.

10. A multi-compartment reagent container in the form of a container strip tapering in an elongated wedge shape between two side walls from a first end wall towards a second end wall, the container having a weakened bridge mounted on at least one end wall, the weakened bridge comprising a member weakened in a central region thereof and supported between two brackets extending outwardly from said end wall, the bridge and the two brackets defining an open area adjacent said end wall.

11. The container of claim 10, wherein: the weakened bridge includes a recess formed near a middle portion of the bridge adjacent to the open area.

12. The container of claim 11, wherein: the weakened bridge also includes a pair of prongs formed at the ends of the bridge that connect to the brackets.

13. The container of claim 12, wherein: the tip is formed on a side of the bridge opposite the recess.