WO2015069544A1

WO2015069544A1 - Sample racks, diagnostic instruments, and operating methods

Info

Publication number: WO2015069544A1
Application number: PCT/US2014/063205
Authority: WO
Inventors: Angela HUENERFAUTH; Alex Hsu; Kung-Le CHANG
Original assignee: Siemens Healthcare Diagnostics Inc.
Priority date: 2013-11-05
Filing date: 2014-10-30
Publication date: 2015-05-14

Abstract

Disclosed is a sample rack including a rack body including one or more sample receptacles adapted to receive one or more sample containers, and one or more thermal regulating units in thermal contact with the rack body and adapted to maintain a desired temperature of the one or more sample containers. Methods of and diagnostic instruments using the sample rack are provided, as are other aspects.

Description

SAMPLE RACKS, DIAGNOSTIC INSTRUMENTS, AND OPERATING METHODS

RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application Serial Number 61/899,902 entitled "SAMPLE RACKS, DIAGNOSTIC INSTRUMENTS, AND OPERATING METHODS" filed on November 05, 2013, the disclosure of which is hereby incorporated by reference in its entirety herein.

FIELD

[0002] The present invention relates generally to testing instruments and sample racks adapted to hold sample containers containing a biological liquid.

BACKGROUND

[0003] In automated medical specimen diagnostic instruments (clinical analyzers and immunoassay instruments) , biological liquids may be provided to the instrument in a sample rack wherein one or more biological liquid sample containers (e.g., one or more blood collection tubes) may be resident in one or more receptacles formed in the sample rack. The sample containers may have been centrifuged to separate the biological liquid (e.g., blood) into its constituent parts, namely into the serum portion and red blood cell (RBC) portion, for example.

[0004] The sample rack containing the one or more biological liquid sample containers is inserted into the testing instrument, and a defined amount of the biological liquid (e.g., the serum portion) may be aspirated, such as by a pipette lowered by a robot. The biological liquid may be dispensed into a test vessel (e.g., a cuvette) along with other components (e.g., one or more reagents, and possibly a diluent) . The reacted test sample may be tested to determine a presence of an analyte, other identifiable substance, or a characteristic thereof.

[0005] During the process of waiting to install the sample rack into the diagnostic instrument, when the sample rack is actually installed in the instrument, and when pipetting operations are taking place within the instrument, handling of the biological liquid contained in the sample containers within the sample rack may cause process variability.

[0006] Accordingly, apparatus, instruments, and methods that may improve handling of the biological liquid contained in the sample containers within the sample rack are desired.

SUMMARY

[0007] According to a first aspect, a sample rack is provided. The sample rack includes a rack body including one or more sample receptacles adapted to receive one or more sample containers, and one or more active thermal regulating units in thermal contact with the rack body and adapted to maintain a desired temperature of the one or more sample containers .

[0008] According to another aspect, a sample rack is provided. The sample rack includes a rack housing including a lower casing forming a reservoir and a removable lid having apertures adapted to receive sample containers formed therein, a rack body including three or more sample receptacles adapted to receive three or more sample containers, the rack body received in the reservoir, and one or more thermal regulating units provided in the reservoir alongside of the rack body and adapted to maintain a desired temperature of the three or more sample containers. [0009] According to yet another aspect, a diagnostic instrument is provided. The diagnostic instrument includes a receiving station adapted to receive a sample rack adapted to contain one or more sample containers including a biological liquid, the receiving station being accessible by a pipette operable to aspirate the biological liquid, and a thermal regulating unit in thermal contact with the sample rack at the receiving station.

[0010] In another aspect, a method of operating a diagnostic instrument is provided. The method includes providing a receiving station within the diagnostic instrument, the receiving station being accessible by a pipette, providing a sample rack adapted to contain one or more sample containers including a biological liquid at the receiving station, and controlling a temperature of the one or more sample containers in the sample rack with a thermal regulating unit in thermal contact with the sample rack while located at the receiving station.

[0011] Still other aspects, features, and advantages of the present invention may be readily apparent from the following detailed description by illustrating a number of example embodiments and implementations, including the best mode contemplated for carrying out the present invention. The present invention may also be capable of other and different embodiments, and its several details may be modified in various respects, all without departing from the scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. The drawings are not necessarily drawn to scale. The invention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1A illustrates a perspective view of a sample rack according to embodiments.

[0013] FIG. IB illustrates a side plan view of a sample rack according to embodiments.

[0014] FIG. 1C illustrates a top plan view of a sample rack according to embodiments.

[0015] FIG. ID illustrates a cross-sectioned end view of a sample rack taken along section line ID-ID of FIG. 1C according to embodiments.

[0016] FIG. IE illustrates an exploded perspective view of a sample rack according to embodiments.

[0017] FIG. 2 illustrates a partially cross-sectioned side view of a sample rack including active thermal control installed within a diagnostic instrument according to embodiments .

[0018] FIG. 3 illustrates a partially cross-sectioned side view of a sample rack installed within a diagnostic instrument including active thermal control according to embodiments.

[0019] FIG. 4A illustrates a schematic side view of a sample rack installed on a diagnostic instrument according to embodiments, ready to be inserted into the diagnostic instrument on a moveable receiving station, and a stand adjacent to the diagnostic instrument adapted to pre-control a temperature of another sample rack waiting to be processed.

[0020] FIG. 4B illustrates a schematic side view of a sample rack installed on a receiving station within a diagnostic instrument according to embodiments, with the receiving station positioned to be accessed by an aspirating/dispensing apparatus . [0021] FIG. 5A illustrates a perspective view of a passive sample rack according to embodiments.

[0022] FIG. 5B illustrates a cross-sectioned end view of a passive sample rack taken along section line 5B-5B of FIG. 5A according to embodiments.

[0023] FIG. 6 illustrates a flowchart of a method of operating a diagnostic instrument according to embodiments.

DETAILED DESCRIPTION

[0024] In some clinical laboratories that process biological liquids, there are some samples that may desire special handling before processing within a diagnostic instrument.

[0025] In particular, in some samples requiring tests, such as tests to determine levels of Ammonium, Troponin, and B-type Natriuretic Peptide (BNP) , the current practice within laboratories is to place the sample on ice, or in a refrigerator separate from the diagnostic instrument, prior to testing in order to refrigerate the sample. However, once the samples are removed from the refrigerator or ice bucket, and loaded into the diagnostic instrument, or while waiting to be loaded, the sample temperature will immediately begin to rise. If the sample resides at the diagnostic instrument for any appreciable time, a temperature of the sample may warm appreciably, and may approach room temperature, which could lead to sample degradation/discordant results. In particular, sample racks received within diagnostic instruments may contain multiple sample containers that contain biological liquid samples, such as five samples or more. Accordingly, not all samples may be processed at once because of the use of conventional sequential pipetting operations. Thus, some of the samples will necessary rise in temperature, and there may be sample-to-sample temperature variations while testing is taking place within the diagnostic instrument. [0026] Thus, in accordance with one embodiment of the present invention, cooling the sample, such as in a cooled sample rack during testing, and even before testing, may prevent the samples from warming.

[0027] In other testing, samples that have Cold Agglutinin or blood thinner may tend to clot prematurely. When the sample is loaded on the diagnostic instrument having an ambient environment at room temperature, the sample may tend to cool and clot, possibly delaying testing due to remedial measure to remove the clot.

[0028] In other instances, it is desired that the samples be maintained at a defined temperature, such as about 37 degrees Celsius. To accomplish this, samples may be placed in an incubator outside of the diagnostic instrument prior to testing to maintain the proper temperature (e.g., heating) . If these samples, that need to be maintained at 37 degrees Celsius (like Cold Agglutinin) , drop to near room temperature, the samples may clot. To remediate, the lab technician may have to remove the sample from the diagnostic instrument, remove the clot, and then re-load the sample back on the diagnostic instrument.

[0029] Thus, in accordance with another embodiment of the present invention, heating the sample during testing, or even preheating the sample, such as in a thermally-controlled sample rack may prevent the samples from clotting prematurely.

[0030] Embodiments of the present invention provide and keep samples at about a desired temperature after they have been loaded into the sample rack. Moreover, some embodiments the desired temperature may be approximately maintained even after being loaded onto the testing system (e.g., diagnostic instrument) . Thus, the samples may be aspirated at optimal temperatures for tests that run optimally at a temperature colder than, or warmer than, room temperature.

[0031] Therefore, embodiments of the invention may: 1) keep the samples at or near a required temperature for a longer period of time, 2) preserve sample integrity, 3) improve accuracy of test results, and 4) in the case of heated samples being provided, provide faster results.

[0032] These and other aspects and features of embodiments of the invention will be described with reference to FIGs. 1A-6 herein .

[0033] In accordance with a first embodiment of the invention, as best shown in FIGs. 1A-1E, a sample rack 100 is provided. The sample rack 100 includes a rack housing 102. Rack housing 102 may include a lower casing 104 forming a reservoir 106

(FIG. IE), and a lid 108 that may be removable from the lower casing 104. Lower casing 104 and lid 108 may be made from an insulating material, such as plastic. Other suitable insulating materials may be used. Extending features 108F

(FIG. IE) may align with receiving features 104F on the lower casing 104 to aid in locating and/or retaining the lid 108 to the lower casing 104. Any suitable features may be used, such as pins and holes, threaded fasteners and holes (e.g., threaded holes) , snap connect features, or other suitable retention features may be used. The lid 108 may include handles 108H at ends to aid the user in gripping the sample rack 100, and apertures 108A that receive the sample containers 114. The lower casing 104 may include suitable connection features 115A, 115B, such as spring tabs shown, to allow the sample rack 100 to be positively located and connected to a receiving station (e.g., receiving station 225) of a diagnostic instrument 201. However, any suitable connection feature (s) may be used. [0034] The sample rack 100 includes a rack body 110 located within the reservoir 106. Rack body 110 includes one or more sample receptacles 112 (a few labeled) adapted to receive the one or more sample containers 114. Sample containers 114 may be bio-liquid collection tubes, such as blood collection tubes. Other suitable sample containers may be received therein. The one or more sample receptacles 112 of the rack body 110 may include three or more, four or more, or five or more sample receptacles 112 that may be arranged linearly, having the centers of the sample receptacles 112 of the rack body 110 lying substantially along a same line. The rack body 110 may include suitable retention features (not shown) to snugly hold the sample containers 114 in the sample receptacles 112. Other numbers of receptacles are possible.

[0035] In the depicted embodiment, one or more active thermal regulating units 116 may be arranged in thermal contact with the rack body 110 and adapted to maintain an approximate desired temperature of the one or more sample containers 114. In some embodiments, where heating of the sample containers 114 is desirable, the one or more active thermal regulating units 116 may be one or more controllable heaters. Each controllable heater may be resistance heater or other suitable heater type. In some embodiments, where cooling of the sample containers 114 is desirable, the one or more active thermal regulating units 116 may be a controllable cooler.

[0036] In some embodiments, where control of a temperature of the sample containers 114 is desirable, the one or more active thermal regulating units 116 may be a Peltier element. In one embodiment, each of the active thermal regulating units 116 is a Peltier element. When a voltage is placed across the Peltier element, one side of the element is cooled, while the other side heats up. By reversing the polarity of the voltage across the Peltier element, the heated and cooled sides of the Peltier element can be reversed. Thus, both heating and cooling may be accomplished and temperature of the sample containers 114 may be regulated.

[0037] In some embodiments, where active control of a temperature of the sample containers 114 is desirable, a thermal sensor 118 may be provided that is adapted to measure a temperature of a portion of the sample rack 100. In one or more embodiments, the thermal sensor 118 may be in direct thermal contact with the rack body 110 at any suitable location. Other suitable locations for the thermal sensor 118 may be used.

[0038] In some embodiments as shown in FIG. ID-IE, first and second active thermal regulating units 116 may be arranged on either lateral side of the rack body 110. Thermal conducting plates 120 may be located on either lateral side of the rack body 110 between the rack body 110 and the respective first and second active thermal regulating units 116. Thermal conducting plates 120 may be made of a high thermal conductance material, such as copper or aluminum. Other suitable thermally conductive materials may be used.

[0039] FIG. 2 illustrates a first embodiment of a diagnostic instrument 201 including a sample rack 100 that is temperature controlled. In particular, the diagnostic instrument 201 includes a receiving station 225 adapted to receive the sample rack 100, which is adapted to contain one or more sample containers 114 including a biological liquid. The receiving station 225 is accessible by a pipette 228 of an aspirating/dispensing apparatus 226 operable to aspirate the biological liquid from the sample containers 114 with the pipette 228. Aspirating/dispensing apparatus 226 may then dispense the biological liquid into another container in the diagnostic instrument 201, such as a reaction cuvette (not shown) . Other conventional portions of the diagnostic instrument 201 are not shown, such as the incubation ring, wash station, cuvette loader, tip storage, testing device (e.g., luminometer or other optical testing system) and the like. A housing (shown dotted) may surround the receiving station 225 and the aspirating/dispensing apparatus 226.

[0040] As shown, the aspirating/dispensing apparatus 226 may include any suitable robot 230. Robot 230 may be configured and adapted to carry out motion of the pipette 228 in one or more coordinate directions, such as Y, X (into and out of the paper), and/or Z. However, typically, the robot 230 may move the pipette 228 in two directions only (e.g., Y and Z) .

[0041] The robot 230 may include one or more robot components (e.g., robot arm(s), link(s), boom(s), frame (s) , or the like) to which the pipette 228 may be mounted to accomplish motion thereof. The robot 230 may be operable by a position controller of a controller 232 to impart the desired motions to the pipette 228 in one dimension, two dimensions, or three dimensions, in order to move and insert the pipette 228 into the sample container 114 (a few labeled) containing a biological liquid, so that at least some biological liquid may be aspirated. The biological liquid may be blood serum, plasma, cerebral liquid, spinal liquid, interstitial liquid, urine, or the like. Other liquids may be aspirated.

[0042] The aspirating/dispensing apparatus 226 may include a pump 235 that may include a pumping chamber (not shown) . For example, pump 235 may be a piston-type pump that may be driven by a suitable motor coupled thereto, such as a stepper motor. Other types of pumps may be used. The pump 235 may be adapted to cause a biological liquid to aspirate into the interior of the pipette 228. The aspiration takes place via operation of the pump 235, which creates an internal pressure to cause flow and aspiration of the biological liquid. The pump 235 may operate using a backing liquid (e.g., purified water) contained within a main supply line 236. Main supply line 236 may include a flexible tube section (e.g., a hollow Teflon tube) along most of its length in some embodiments. Backing liquid may be supplied by a liquid supply (not shown) .

[0043] Aspiration controller of the controller 232 may be adapted and operational to control the motor, and thus the pump 235 to draw in (e.g., aspirate) a desired amount of the biological liquid into the interior of the pipette 228. Aspiration controller of the controller 232 may also control the dispensing operations performed by the aspirating/dispensing apparatus 226. The aspirating/dispensing apparatus 226 may include other conventional components, such as one or more valve (s), accumulator ( s ) , distributors, or other hydraulic components (not shown) to effectuate the liquid aspirating and dispensing. A pressure sensor 238 may be coupled to the main supply line 236 and used to provide a pressure signal to the aspiration controller to verify proper aspiration. Any suitable apparatus for aspirating the liquid into the pipette 228 may be used. For example, aspirating/dispensing apparatus that may be used with the present invention are described in US Patents 7,867,769; 7,634,378; 7,477,997; 7,186,378; 7,150,190; and 6,370,942.

[0044] In one broad aspect, one or more active thermal regulating units 116 are provided in thermal contact with the sample rack 100 while the sample rack 100 is installed at the receiving station 225. In the depicted embodiment, the one or more active thermal regulating units 116 are "active" thermal regulating units and are formed as a part of the sample rack 100, as is shown and described in FIGs. 1A-1E. However, as will be apparent, the one or more active thermal regulating units 316 may be a part of the diagnostic instrument 301 in some embodiments (See FIG. 3) . [0045] In the depicted embodiment of FIG. 2, a thermal controller 234 of the controller 232 is coupled to the one or more active thermal regulating units 116. The thermal controller 234 may include a set point that may be set by the operator depending upon the set temperature that is desired for the particular test being run on the samples. Thermal controller 234 may include a suitable processor and memory, power supply, one or more drivers, D/A converters, and suitable electronics to cause the desired current to be supplied to the one or more active thermal regulating units 116.

[0046] In cases where the active thermal regulating unit 116 is a Peltier element, polarity changing electronics may be provided that are responsive to a measured temperature signal supplied from the thermal sensor 118. Conventional sensor signal processing electronics may be provided. The thermal sensor 118 may be provided in thermal contact with one or more of the active thermal regulating units 116, on the rack body 110, or elsewhere in the sample rack 100, and may provide a measured temperature signal in line 239. Line 239 may electrically couple to the thermal sensor 118 through one or more electrical connectors 242A (e.g., leaf springs) that couple to a contact pad set 122A, 122B (FIG. 1A) formed on the rack housing 102. Contact pad set 122A, 122B (only one shown in FIG. 1A) may be coupled, such as by wires in the reservoir 106, to the poles of the thermal sensor 118. Another contact pad (not shown) , like contact pad 122A, may be provided on the opposite side of the rack housing 102. Installation of the sample rack 100 at the receiving station 225 of the base element 244 may simultaneously make the power connection and electrical connection to the thermal sensor 118.

[0047] As shown in FIG. 2, power may be provided to the active thermal regulating units 116 within the reservoir 106 by suitable power lines 240A, 240B. Power lines 240A, 240B may make electrical connection to the active thermal regulating units 116 through power contacts 124A and 124B (124B not shown in FIG. 1A) and electrical connectors 242A, 242B in base element 244. Active thermal regulating units 116 may be wired in an electrical parallel orientation. Other suitable electrical power and sensor connections may be used, such as plugs or the like.

[0048] In an alternative configuration as is shown in FIG. 3, one or more active thermal regulating units 316 may be provided as a part of the diagnostic instrument 301. In particular, the active thermal regulating unit 316 (or units) may be mounted to a base element 344 of the diagnostic instrument 301. Base element 344 may be a tray including a receiving station 325 having a configuration adapted to receive and retain a sample rack 300 in a desired location within the diagnostic instrument 301. In particular, the receiving station 325 may be positioned on the base element 344 at a position that is accessible by the pipette 228 of the aspirating/dispensing apparatus 226. The aspirating/dispensing apparatus 226 may be the same as before described. Base element 344 may include a pocket or other retaining feature adapted to receive the thermal regulating unit 316 (or units) therein. Base element 344 and sample rack 300 may include retention features, which provide physical restraints (e.g., snap fit) that causes the sample rack 300 to be positioned on, and be immovable relative to, the base element 344.

[0049] Thermal sensor 318 may be provided in thermal contact with one or more of the active thermal regulating units 316 and may provide a temperature signal in line 339. The thermal controller 234 of the controller 232 is electrically coupled to the active thermal regulating unit 316 and is operable as discussed above. Power may be provided to the active thermal regulating unit 316 by suitable power line 342.

[0050] In operation, the depicted embodiment the sample rack 300 may be placed on the on the active thermal regulating unit 316 (e.g., a Peltier element) and the sample rack 300 can be controlled to an approximate desired set temperature. In this embodiment, the sample rack 300 is a passive sample rack

(including no active, i.e., powered, heating or cooling elements) . However, sample rack 300 may include thermal conducting plates 320 that may be in thermal contact with the active thermal regulating unit 316 and the rack body 310 containing the sample containers 114. Except for thermal conducting plates 320, which may extend through a bottom of the housing 302, the sample rack 300 is a passive sample rack and is the same as is described below with reference to FIGs. 5A and 5B herein.

[0051] In another embodiment, the sample rack 100, 300 can be placed on a stand 450, which is positioned alongside of the diagnostic instrument 201, 301, as is shown in FIGs. 4A-4B. Stand 450 may include the same structure as the base element 244 or 344. By placing the sample rack 100, 300 on the stand 450, the sample rack 100, 300 can be pre-conditioned (e.g., pre-heated or pre-cooled) to the desired temperature. Power to, and control of, the active thermal regulating unit(s) within the sample rack 100 or stand 450 may be provided by a supply cord 451 coupled to the controller of the diagnostic instrument 201, 301.

[0052] FIG. 4A illustrates the base element 244, 344 retracted from the diagnostic instrument 201, 301 and positioned to accept a sample rack 100, 300. FIG. 4B illustrates the base element 244, 344 positioned back within the diagnostic instrument 201, 301 such that the sample rack 100, 300 is accessible by the pipette 228 of the aspirating/dispensing apparatus 226 and the aspiration may take place. Base element 244, 344 may be slid into the diagnostic instrument 201, 301 on one or more rails or other slide elements, and may be secured, retained, or locked in place. In this embodiment, Y axis capability of the robot 230 will allow access to the sample containers in the sample rack 100, 300. Optionally, the base element 244, 344 may be automatically moveable on the slide under the action of another motor (not shown) carrying out Y axis motion to position the sample rack 100, 300 at the desired location for the pipette 228 accessing a particular sample container 114.

[0053] FIGs. 5A and 5B illustrate an embodiment of a sample rack 500 which is "passive," i.e., that includes only one or more passive (non-powered) thermal regulating units 516. The sample rack 500 includes a rack housing 502 including a lower casing 504 forming a reservoir 506, and a removable lid 508 having apertures 508A (a few labeled) adapted to receive sample containers 114. Sample rack 500 further includes a rack body 510 including three or more sample container receptacles 512 adapted to receive three or more sample containers 114 therein. The three or more sample container receptacles 512 may be arranged linearly, as shown. The rack body 510 may be centrally received within the reservoir 506 in some embodiments, and may be formed either separately from, or integrally with, the lower casing 504.

[0054] The one or more thermal regulating units 516 are provided in the reservoir 506 alongside of the rack body 510, such as one on each lateral side, as shown. The one or more thermal regulating units 516 are adapted to maintain an approximate desired temperature of the three or more sample containers 114 in the rack body 510. In the depicted embodiment, the one or more thermal regulating units 516 may comprise one or more gel packs. The one or more gel packs may include a plastic skin and a contained gel filler material such as hydroxyethyl cellulose or vinyl-coated silica gel. Other suitable gel filler materials may be used.

[0055] Like the "active" sample rack 100 discussed above, the "passive" sample rack 500 may include thermal conducting plates 520 that may be located on either lateral side of the rack body 510. User may open the removable lid 508, insert the gel packs, and reclose the removable lid 508. The rack housing 502 may include retention features 545 on either end that engage with corresponding features at a receiving station within the diagnostic instrument. Thus, in the "passive" embodiment, the sample rack 500 may be placed directly into the receiving station of a diagnostic instrument at a location accessible by the pipette 228, and the samples containers 114 and biological liquid samples therein can continue to be maintained close to a desired temperature even after installation into the diagnostic instrument. Where the one or more thermal regulating units 516 comprise one or more gel packs, the gel packs may be frozen where cooling of the sample containers 114 in the rack body 510 is desired, or microwaved or otherwise heated where some level of heating of the sample containers 114 is desired.

[0056] According to another aspect, a method of operating a diagnostic instrument according to embodiments will now be described with reference to FIG. 6. The method 600 includes, in 602, providing a receiving station (e.g., receiving station 225, 325) within the diagnostic instrument (e.g., diagnostic instrument 201, 301), the receiving station being accessible by a pipette (e.g., pipette 228) . Pipette 228 may be part of an aspirating/dispensing apparatus 226.

[0057] The method 600 includes, in 604, providing a sample rack (e.g., sample rack 100, 300, 500), that is adapted to contain one or more sample containers (e.g., sample containers 114) including a biological liquid, at the receiving station.

[0058] The method 600 includes, in 606, controlling a temperature of the one or more sample containers in the sample rack with a thermal regulating unit (e.g., one or more "passive" or "active" thermal regulating units 116, 316, 516) in thermal contact with the sample rack while at the receiving station .

[0059] In accordance with one or more embodiments, the thermal regulating unit may be an active thermal regulating unit

(e.g., active thermal regulating unit 116, 316) as described with reference to FIGs. 1A-1E, FIG. 2, and FIG. 3 where temperature is controlled by a signal from a thermal controller (e.g., thermal controller 234) coupled to the active thermal regulating unit. The active thermal regulating unit may be provided within the sample rack 100, as in the FIG. 2 embodiment, or within and as a part of the diagnostic instrument 300 as in the embodiment of FIG. 3.

[0060] Having shown the preferred embodiments, those skilled in the art will realize many variations are possible that will still be within the scope of the claimed invention. Therefore, it is the intention to limit the invention only as indicated by the scope of the claims.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A sample rack, comprising: a rack body including one or more sample receptacles adapted to receive one or more sample containers; and one or more active thermal regulating units in thermal contact with the rack body and adapted to maintain a desired temperature of the one or more sample containers.

2. The sample rack of claim 1, wherein the one or more active thermal regulating units comprises a controllable heater .

3. The sample rack of claim 1, wherein the one or more active thermal regulating units comprises a controllable cooler .

4. The sample rack of claim 1, wherein at least one of the one or more active thermal regulating units comprises a Peltier device.

5. The sample rack of claim 1, comprising a thermal sensor adapted to measure a temperature of a portion of the sample rack .

6. The sample rack of claim 1, wherein the rack body comprises : three or more sample receptacles arranged linearly, and first and second active thermal regulating units arranged on either lateral side of the rack body.

7. The sample rack of claim 1, comprising: thermal conducting plates located on either lateral side of the rack body.

8. A sample rack, comprising: a rack housing including a lower casing forming a reservoir and a removable lid having apertures adapted to receive sample containers formed therein; a rack body including three or more sample receptacles adapted to receive three or more sample containers, the rack body received in the reservoir; and one or more thermal regulating units provided in the reservoir alongside of the rack body and adapted to maintain a desired temperature of the three or more sample containers.

9. The sample rack of claim 8, wherein the one or more thermal regulating units comprise one or more gel packs.

10. The sample rack of claim 9, wherein the one or more gel packs comprise hydroxyethyl cellulose or vinyl-coated silica gel .

11. The sample rack of claim 8, wherein the one or more thermal regulating units comprises a controllable heater.

12. The sample rack of claim 8, wherein the one or more thermal regulating units comprises a controllable cooler.

13. The sample rack of claim 8, wherein at least one of the one or more thermal regulating units comprises a Peltier device .

14. The sample rack of claim 8, comprising: thermal conducting plates located on either lateral side of the rack body.

15. The sample rack of claim 8, comprising a thermal sensor adapted to measure a temperature indicative of the sample rack .

16. A diagnostic instrument, comprising: a receiving station adapted to receive a sample rack adapted to contain one or more sample containers including a biological liquid, the receiving station being accessible by a pipette operable to aspirate the biological liquid; and a thermal regulating unit in thermal contact with the sample rack at the receiving station.

17. The diagnostic instrument of claim 16, wherein the thermal regulating unit is an active thermal regulating unit.

18. The diagnostic instrument of claim 17, wherein the active thermal regulating unit is a part of the sample rack.

19. The diagnostic instrument of claim 17, wherein the active thermal regulating unit is a part of the diagnostic instrument .

20. The diagnostic instrument of claim 17, comprising a thermal controller coupled to the active thermal regulating unit .

21. A method of operating a diagnostic instrument, comprising : providing a receiving station within the diagnostic instrument, the receiving station being accessible by a pipette ; providing a sample rack adapted to contain one or more sample containers including a biological liquid at the receiving station; and controlling a temperature of the one or more sample containers in the sample rack with a thermal regulating unit in thermal contact with the sample rack while located at the receiving station.

22. The method of claim 21, wherein the thermal regulating unit comprises an active thermal regulating unit and the temperature is controlled by a signal from a thermal controller coupled to the active thermal regulating unit.