Background of the Invention Reaction vessels or cuvettes are known in the field of"wet"chemistry clinical analysis systems for retaining a plurality of patient samples and other fluids for the preparation and conduction of various types of assays.

As described in U. S. Patent No. 4,690, 900 to Kimmo et al. , these vessels typically include a support fixture having a plurality of adjacently disposed reaction wells, each of the wells being sized to retain a volume of a metered fluid, such as patient sample, diluent, reagent (s), and/or calibration fluids. As described in the above referred to'900 patent, the fluid (s) retained in each of the reaction chambers can be tested as needed by apparatus, such as a spectrophotometer, through a transparent window provided in the side walls of the vessel.

A problem generally known to those in the field of patient sample measurement is that heat transfer will take place between adjacent chambers of a reaction vessel which conducts multiple wet assays. Such thermal effects influence not only the confidence in testing using the vessel, but also the overall throughput of a clinical analysis apparatus used in conjunction therewith.

Therefore, there is a general need in the field to minimize the thermal effects between individual samples within a reaction vessel or cuvette; that is, to be able to thermally insulate the fluid contents within a vessel which contains a plurality of adjacently disposed reaction wells or chambers.

There is another general need in the field to improve the manner in which sample or other fluid is dispensed into one or more reaction chambers of a reaction vessel, such as those previously described above.

Summary of the Invention It is a primary object of the present invention to overcome the above- noted problems associated with the prior art.

It is another primary object of the present invention to provide a reaction vessel or cuvette for processing of wet assays in which the fluid contents of adjacent reaction chambers of the vessel are thermally insulated from one another.

It is yet another primary object of the present invention to provide a reaction vessel which permits greater controlled aspiration and dispensing of fluids used in the conduction of wet assays.

It is still a further primary object of the present invention to provide greater throughput for clinical analytical apparatus in which wet assays are performed.

Therefore and according to a preferred aspect of the invention, there is provided a reaction vessel comprising: a) a frame including a plurality of vertically disposed reaction chambers held in spaced relation, each of said reaction chambers being sized for retaining a volume of at least one fluid; and b) means disposed between at least two adjacent reaction chambers for thermally affecting the fluid contents thereof.

The thermal affecting means according to a preferred embodiment includes at least one gap region which is defined between at least two adjacent reaction chambers of the reaction vessel. Preferably, the gap region includes at least one air or evacuated gap that prevents or at least substantially minimizes migratory or transient thermal effects to therefore provide improved insulation for the fluid contents of the vessel.

According to a preferred embodiment, the lower portion of each reaction chamber of the herein described vessel is smaller than the upper portion, the reaction chamber being sized to receive a fluid dispensing or aspirating member, such as a tapered disposable metering tip, which can aspirate fluid from or dispense fluid to a reaction chamber.

Preferably, the reaction chambers each include at least one pair of optically transmissive windows, preferably located in the lower portion of each reaction chamber of the vessel, which allows spectrophotometric or other form of optical testing to be performed on a retained fluid sample.

The thermal affecting means can also be used to conduct heat more readily to at least one reaction chamber of the herein described vessel. For example, an adapter block made from a thermally conductive material can be placed into at least one of the defined gap regions. When inserted into an incubator, thermal transfer readily occurs between the reaction chambers adjacent the gap region containing the thermally conductive adapter block.

Alternately, the incubator can be configured to engage the gap regions of the reaction vessel directly so as to selectively apply heat directly to any number of thermal chambers of the vessel.

According to yet another preferred aspect of the invention, there is provided a reaction vessel for use in a clinical analyzer, said reaction vessel comprising a frame including a plurality of vertically disposed reaction chambers in spaced relation, each of said reaction chambers being sized for retaining a volume of fluid and means disposed between at least two of said chambers for thermally insulating the fluid contents in at least one pair of reaction chambers.

Preferably, the thermal insulating means can include at least one gap region disposed between at least one pair of the reaction chambers.

In addition, at least one of the reaction chambers is sized to receive a fluid dispensing/aspirating member, such as a pipette tip in order to dispense fluid into a reaction chamber directly or to aspirate fluid therefrom.

According to a preferred embodiment, the fluid dispensing/aspirating member is a disposable tapered metering tip.

The cuvette is preferably made from a plastic material and includes at least one transparent window pair to permit optical testing of fluid sample contained in at least one of the reaction chambers of the vessel.

According to yet another preferred aspect of the present invention, there is provided a clinical analyzer comprising a wet chemistry analysis system and at least one reaction vessel for retaining at least one fluid sample. The reaction vessel includes a plurality of reaction chambers, each of the chambers having defined therebetween thermal affecting means which insulates the fluid contents of the reaction chambers or enables thermal transfer to occur readily to or between reaction chambers when used in conjunction with an incubator of the analyzer.

According to yet another preferred aspect of the invention, there is described a method for testing a patient sample, said method comprising the steps of: a) providing a reaction vessel having a plurality of adjacent reaction chambers, b) aspirating a fluid into a fluid aspirating/dispensing member; c) introducing said fluid aspirating/dispensing member into a lower portion of a reaction chamber; and d) dispensing fluid directly into the lower portion of the reaction chamber of said vessel.

Preferably, fluid, such as patient sample, reagents, or calibration liquids, can also be selectively aspirated from a reaction chamber, also preferably using a fluid aspirating/dispensing member, such as a tapered metering tip, which is lowered into a reaction chamber.

An advantageous feature of the present invention is that multiple fluid volumes which are contained within a reaction vessel in separate reaction chambers of the vessel can be thermally isolated from one another.

Another advantage of the present invention is that each of the reaction chambers of the reaction vessel can be used to receive a metering tip to either aspirate or dispense sample or other fluids therefrom.

Yet another advantage of the present invention is that overall throughput can be effectively increased using a reaction vessel, such as described herein, in a clinical analyzing apparatus.

These and other objects, features, and advantages will become readily apparent from the following Detailed Description which should be read in conjunction with the following drawings.

Brief Description of the Drawings Fig. 1 is a side elevational view, partly in section, of a reaction vessel made in accordance with the prior art; Fig. 2 is a side elevational view of the prior art reaction vessel of Fig. 1 as used in conjunction with an optical testing apparatus; Fig. 3 is a top view of a reaction vessel made in accordance with a first embodiment of the present invention; Fig. 4 is a sectioned front perspective view of the reaction vessel of Fig.

3; Fig. 5 is a side sectional view of the reaction vessel of Fig. 4 including a metering tip which can be fitted into a reaction well of the vessel; Fig. 6 is a side elevational view, in section, of a reaction vessel in accordance with a second embodiment of the present invention; Fig. 7 is a top perspective view of an adaptive assembly which can be fitted into the vessel of Fig. 6; and Fig. 8 is a partial side perspective view, in section, of a reaction vessel made in accordance with a third embodiment of the present invention.

Detailed Description The following description relates to certain preferred embodiments of a reaction vessel or cuvette, preferably for use with an automated clinical analyzer. Throughout the course of discussion, it will be readily apparent to one of sufficient skill that there are various modifications and variations which embody the inventive concepts.

Referring to Fig. 1, and for purposes of background there is first described a prior art reaction vessel 10, the vessel including a plurality of adjacently spaced reaction wells or chambers 14. The vessel 10 permits optical testing of the fluid contents contained within the reaction wells 14 using an apparatus 20, which according to this embodiment is a spectrophotometer or other device capable of measuring an optical property through the side walls of the vessel. Each of the reaction wells 14 of the vessel 10 are generally uniform rectangular sections which include an open top or upper end 24 and a bottom wall 25, each of the reaction wells being separated from one another by respective walls 26 of plastic material.

Referring now to Figs. 3-5, there is described a reaction vessel 40 made in accordance with a first preferred embodiment of the present invention. The reaction vessel 40 includes a support frame 44, manufactured preferably from a moldable plastic such as polystyrene, acrylic, polyamide, polycarbonate, or other similar material. Though plastic makes the cuvette 40, the vessel could also be made from other materials such as glass or metal. The support frame 44 includes a plurality of adjacent open-ended reaction wells or chambers 48, each of which in a preferred embodiment are equally spaced in relation to one another.

According to the present embodiment, six (6) reaction chambers 48 are provided, though it will be appreciated that this number can be suitably varied depending on the application or use of the vessel.

The support frame 44 according to this particular embodiment is rectangular in shape and defined by a pair of side walls 52, and a pair of

opposing end walls 56. Each of the reaction chambers 48 are defined by a substantially cylindrical cross section and include an open-ended upper portion 64 and a narrower lower portion 68 including a bottom wall 60. The upper and lower portions 64,68 of each interior reaction chamber 48 include interior opposing end walls 69 which are substantially parallel to one another, with the exception of a tapered portion 72 linking the upper and lower portions together. The exterior reaction chambers of the vessel 40 include one interior end wall 69 and an end wall 56. In addition, the reaction chambers 48 according to this present embodiment are sized to accommodate a fluid aspirating/dispensing member 76. In this instance, the fluid aspirating/dispensing member 76 is a tapered disposable metering tip 76, such as those manufactured by Johnson and Johnson Company under the trade name Vitros though it should be apparent to one of sufficient skill that other forms of pipette tips can alternately be substituted using the inventive concepts of the invention.

It should or will become"readily apparent that the need for the tapered portion 72 is based, in large part, on the geometry of the tip 76 and is not essential if other tips are used. Furthermore, other shapes of the vessel 40 could be assumed rather than only rectangular.

The end walls 56,69 of each of the reaction chambers 48 are thickened to support the weight of the fluid volume and are formed using conventional molding techniques. In addition, the side walls 52 of the plastic support frame 44 of the herein described reaction vessel 40 also form the side walls for each of the reaction chambers 48. At least a portion 82 of each of the side walls 52 is made optically transparent to permit light to be transmitted through the lower portion 68 of each reaction chamber 48 and permit optical testing of a retained fluid sample, using for example, a spectrophotometer, such as that shown partially in Fig. 2, above. Details relating to this form of testing are provided in U. S. Patent No. 4,690, 900, the entire contents of which are incorporated herein. The entirety of the

support frame 44, including the interior end walls 69 are preferably transparent, though it should be realized that this is not essential. In fact, if required, each of the interior end walls 69 or other portions of the vessel could be made to form a light lock to prevent light transmissibility between interior chambers 48.

Due to the disparity in size between that of the narrowed lower portion 68 and the upper portion 64 of each of the reaction chambers 48 according to this embodiment, a gap region 78 is formed between each pair of adjacent interior reaction chambers 48. According to the present embodiment, a total of five (5) gap regions 78 are provided, each having a tapered shape or cross section. In addition, smaller gap regions 75 are provided between each of the end walls 56 and each end reaction chamber 48.

According to this embodiment, the disposable metering tip 76 can aspirate patient sample from a supply (not shown) through use of a conventional metering system (not shown) including a probocsis and a metering transport rail. Alternately, the sample could be supplied manually.

The tip 76 can then be placed directly into a reaction chamber 48 such that the dispense end of the tip is placed directly into the lower portion 68 for dispensing of the liquid. The tip 76 can then be withdrawn and discarded or washed. A new tip (not shown) can then aspirate additional fluids, such as reagent or calibration fluids which can also be dispensed into the reaction well 48 for conduction of the assay. The cuvette 40 can then be inserted into an incubator (not shown) and the fluid contents can be optically read in accordance to the protocol of the assay being performed.

The present reaction vessel 40 is a single use cuvette. Therefore, the reaction vessel 40, following conduction of the multiple assays and testing thereof, can be discarded.

It should be noted that the gap regions can assume other geometries, such as those shown in Figs. 6 and 7, among others. It should be readily

apparent that these illustrations are not exhaustive as numerous gap designs are possible.

Referring back to Figs. 3-5, the gap regions 78 of the herein described reaction vessel 40 contain air which serves to insulate the contents between adjacent lower portions 68 of the reaction chambers 48 of the reaction vessel 40.

Alternately, each of the gap regions 78 could be evacuated in order to create a vacuum to vary the amount of thermal insulation between adjacent reaction chambers 48.

The smaller gap regions 75 serve a separate function to thermally isolate the cuvette from the heated end surfaces of incubator (not shown).

The reaction vessel can also be used to otherwise thermally affect the fluid contents of any of the reaction wells 48. Referring to Fig. 6, a reaction vessel or cuvette 80 made in accordance with a second embodiment of the present invention is herein described. As in the preceding, the reaction vessel 80 includes a support frame 84 which is defined by a plurality of adjacent reaction chambers 88. Each of the reaction chambers 88 are. sized to retain a volumetric quantity of fluid and include respective upper and lower portions 92,96 separated by a tapered portion 100. A number of gap regions 104 are provided between each of the lower portions 96 of the vessel 80.

According to this embodiment, a corresponding number of adapter elements 108 (only one of which is shown) are sized to be fitted within a defined gap region 104 of the reaction vessel 80. Each of the adapter elements 108 are made from copper or other highly thermally conductive material which can be either selectively implanted in order to speed reaction time and/or hasten the temperature in conjunction with an incubator of the clinical analyzer in order to improve processing times.

Referring to Fig. 8, a reaction vessel according to a third embodiment is herein described. This reaction vessel 120, as in the preceding

embodiments, includes a support frame 124, only partially shown, which includes a plurality of adjacent reaction chambers or wells 128 includes a number of gap regions 132 which according to this embodiment, extend over the entire height of the vessel. The gap regions 132 as shown are air gaps which provide thermal insulation between adjacent reaction wells. However, each of the gap regions 132 could be alternately provided with an adapter element 138 made from a highly thermally conductive material.

Parts List for FIGS. 1-7 10 reaction vessel 14 frame 18 reaction wells or chambers 20 apparatus 24 open end 26 separating walls 40 reaction vessel 44 support frame 48 reaction chambers or wells 52 side walls 56 end walls 60 bottom wall 64 upper portion 68 lower portion 69 end walls 72 tapered portion 75 gap regions 76 fluid aspirating/dispensing member 78 gap region 80 reaction vessel or cuvette 82 optically transparent portion 84 support frame 88 reaction chambers 92 upper portion 96 lower portion 100 tapered portion 104 gap regions 108 adapter elements 120 reaction vessel 124 support frame 128 reaction chambers or wells 132 gap regions 138 adapter elements 142 adapter plate 143 adapter elements It should be readily apparent that other modifications and variations are possible which embody the inventive concepts of the invention. For example, and rather than employing insertable or integral adapter elements, a clinical analyzer could include an incubator having a heating plate or plate adapter 142 which engages the gap regions of the reaction vessel as shown in Fig. 7 and whereby any two or more chambers not necessarily adjacent can be thermally connected by appropriately locating the adapter elements 143 on adapter plate 142.