US20090098593A1

US20090098593A1 - Laboratory plate thermal vault

Info

Publication number: US20090098593A1
Application number: US12/130,710
Authority: US
Inventors: Rolf Ehrhardt; Brian Schryver; Jeff Schryver
Original assignee: Biocision LLC
Current assignee: Cool Lab LLC
Priority date: 2007-10-15
Filing date: 2008-05-30
Publication date: 2009-04-16
Also published as: US8388912B2; US20090258407A1

Abstract

A portable temperature transfer device for transferring thermal energy to and/or from a laboratory plate is provided as well as its methods of use. The temperature transfer device comprises a base and a raised stage that comprises a thermal conductive material and an encasement that interfaces with the base to create a cavity that encloses a laboratory plate. The raised stage allows direct contact between individual wells of the laboratory plate and the temperature transfer device. The encasement completes the thermally conductive environment for the laboratory plate.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of commonly assigned, copending U.S. patent application Ser. No. 60/980,167 filed Oct. 15, 2007.

FIELD OF THE INVENTION

The invention relates to temperature transfer devices and methods for using the same. In particular, some aspects of the temperature transfer devices are adapted to be used with various laboratory or cell culture plates.

BACKGROUND OF THE INVENTION

Many chemical, binding, and molecular biological reactions, as well as in vitro culture of cells or tissue, require maintaining proper conditions such as temperature and humidity. In research or laboratory settings, often laboratory or cell culture plates (hereinafter simply “laboratory plates”) are used.
The laboratory plates generally comprise a plurality of wells that are designed, for example, to hold cells or tissues in culture medium; biological, experimental or production reactions; biological or chemical reaction assays or diagnostic assays. For cell culture, typically, a cell is placed in a culture fluid in a floating state, or a cell is fixed to an inside or a surface of a gel in which an ingredient of the culture fluid is added. Alternatively, the cell is transplanted in a material such as a matrix, a scaffold, a carrier or a mold. The cells are then allowed to proliferate and grow within the laboratory plates under proper conditions. For experimental reactions, laboratory plates are typically used as containment and reaction vessels that can allow for multiple instances of a process to be organized onto useful collections. For example in an ELISA assay, target proteins can be bound to the bottom of multiple well plates and the level of the target protein present in each well can be determined by the binding of enzyme-linked antibodies to the target protein followed by a colorimetric readout assay.
While laboratory plates are useful in holding cells and reactions separate from those in other wells, the overall design of laboratory plates makes it difficult to control the temperature. To control the cell culture or reaction temperature, typically the entire laboratory plate is placed in a temperature controlled environment such as an incubator, an oven, a refrigerator, a freezer or a container filled with ice. Thus, conventional methods for controlling the temperature of laboratory plates requires a relatively large apparatus compared to the size of laboratory plates for temperature control. Furthermore, these temperature control devices are generally not readily portable nor are these methods very quick or easy to conduct in a sterile environment (e.g. under a laboratory hood). Further, the arrangement of the wells in an array pattern will impose a different surrounding environment on the wells depending on their position in the array. For example, a well near the center of the array will be entirely surrounded by other wells while a well on the array edge will be not have adjacent wells on all sides, and a well on a corner of the array has still fewer wells directly adjacent. In addition, wells on the plate periphery are positioned close to the skirt by which the plate is in direct contact with the surface on which the plate is resting. The variable environment of the wells imposes a differential in physical states, including temperature, thermal transfer, humidity, gas exchange, pH, static electric charge, and light exposure, based on position of the well.
Many experimental routines involved with the use of laboratory plates are devised for increasing productivity while maintaining an environment conducive to respected biological or chemical practices. Although these routines are set up to maximize throughput, problems are often encountered that produce less than satisfactory conditions for conducting experimental assays. One of the problems that can contribute to reduced productivity is what is commonly referred to in the art as “edge effects”. Edge effects are caused by well to well variation in thermal energy transfer, gas exchange, pH balance, water loss, static charge, and light exposure that result due to the relative physical position of the well on the plate. Edge effects are typically handled by exclusion of data in the outside wells of the plate, or by compensatory methods that include, for example; allowing plated cells to attach undisturbed at room temperature (which is at the same time is deleterious to many types of cultured cells), humidification methods such as closed chambers, restriction of access to incubators or addition of liquid to inter well space on the plate. The problem remains largely unresolved for most applications.
It is also recognized in the literature that differences in relative temperatures between the reactant liquid, the holding vessel, and the surrounding environment can have effects on brief substrate reactions such as incubation in ELISA tests. For example, in one multi-well reaction plate manufacturers bulletins (Nunc bulletin no. 1 second edition 1997) circumstances which can cause positive edge effects, i.e. unexpectedly higher optical densities in peripheral wells than in central wells of a MicroWell matrix due to these temperature differences. Likewise, negative edge effects can also occur which result in an unexpectedly lower optical density.
In a technical bulletin entitled “Negative Edge Effect in MICROWELL ELISA” by Nalge Nunc International the combinations of temperatures in the reactant, well, and environment and their likely influence on edge effects are described. In the described experiment a negative edge effect was observed when the wells of the reaction plate were not adjusted to ambient temperature of the reactant liquid. The paper concludes that “Obviously, to eliminate edge effect, not only the reactant liquid should be adjusted to the temperature intended for incubation, but also the wells per se.” In this experiment the edge effect differences between corner wells and central wells were as high as 17%.
The bulletin does not, however, provide a method of adjusting the temperature of the wells. Moreover, it does not recognize that the problem in positive and negative edge effects is not the temperature difference between the environment, reactants and well as the paper teaches. The true cause of edge effects is the temperature differential between wells with time. Thus, a more complete solution to the problem is not to adjust the plate to room temperature before substrate reaction, but rather to ensure that each well undergoes substantially identical thermal history as the rest of the wells in the plate. Ensuring substantially equivalent thermal history removes the requirement for equilibration of the reactant, well, and environment.
In addition to thermal energy control on laboratory plates, the effects of differences in local humidity and water loss can be significant. Plate wells that are closer to the edge of the plates have a greater opportunity for water vapor loss due to evaporation than the wells near the center of the plate. As a result, visible differences in the liquid level in wells can be observed following a time interval. The water loss incurred can induce additional changes including changes in reaction component concentrations, changes cell medium component concentrations, alteration the pH of the solution, deposition of solubilized components on well walls, shift equilibrium balances of reactions and alteration of heat transfer properties.
Many cell culture mediums control the solution pH through a carbonate buffer system in which the carbonate buffer system is in equilibrium with gaseous CO₂in the immediate environment. Multi-well culture plates typically include a cover plate that maintains sterility inside the wells and allows gas exchange by the inclusion of stand-off protrusions inside the plate that create a gap between the plate and the underside of the encasement. This arrangement places wells on the periphery of the plate in a position of enhanced gas exchange compared to wells toward the middle of the plate. As a result, there can be differences in the pH of the wells in moving from the periphery to the interior wells of the plate. Further, currently available incubators are insufficiently designed to prevent evaporation from the edge wells and within an incubator, conditions can vary between shelves and even between locations on the same shelf.
Many FACS based assays involve the use of cultured cells to which are bound fluorescently-tagged antibodies. During the incubation period light must be excluded from the plate to prevent photo-bleaching of the fluorescent tag molecules. The most common method of light exclusion is through the use of a light-proof box cover or aluminum foil.
Therefore, there is a need for a device that controls temperature, light, gas and humidity for laboratory plates that is portable, relatively small and provides even thermal energy transfer, humidification, gas exchange and light exclusion for all of the wells in any experimental environment.

SUMMARY OF THE INVENTION

The object of the instant invention is to ensure rapid heat transfer between the thermal vault and multi-well laboratory plate and establish temperature equilibration in each of the wells in the laboratory plate, such that each well undergoes substantially the same thermal history.
Another object of the instant invention is to create an enclosed environment to protect the laboratory plate from transient environmental temperature changes.
Another object of the instant invention is to act as a temperature equilibration storage system, such that a laboratory plate can be removed from one environment, and transferred to another environment at some later time without changes in the internal temperature of the laboratory plate wells.
Another object of the instant invention is to provide a temperature control device that is readily portable and amenable for work conducted in a variety of different environments (e.g. under a laboratory hood).
Another object of the invention is to provide a common surrounding environment for the wells of a laboratory plate regardless of their position in the array of plate wells. The constant environment provided by the instant invention enables greater consistency in the established physical states of each well, including temperature, thermal transfer, humidity, gas exchange, pH, static electric charge, and light exposure, based on position of the well.
Another object of the instant invention is provide increased productivity with laboratory plate-based assays by reducing “edge effects” caused by well to well variation in thermal energy transfer, gas exchange, pH balance, water loss, static charge, and light exposure that result due to the relative physical position of the well on the plate.
These and other objects of the present invention are achieved in a portable temperature transfer device typically comprising a base, a stage located on top of said base and an encasement that rests on the stage and encloses the stage. The stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy from the temperature control device to the plurality of laboratory plate wells and is adapted to be in contact with at least the bottom surface of the laboratory plate wells when the laboratory plate is placed on top of said portable temperature transfer device. The encasement also comprises a thermo-conductive material to replicate the base plate temperature and fits into a groove created around the perimeter of the stage such that when the laboratory encasement is placed on top of the stage, the stage prevents any significant lateral movement of the encasement relative to the base.
In some embodiments of the present invention, the stage is adapted to be operatively connected to a temperature control device.
In another embodiment of the present invention, a method is provided for adjusting temperature of a laboratory plate, which comprises a plurality of wells. The method generally comprises placing the laboratory plate on a portable temperature transfer device, wherein the portable temperature transfer device comprises a base and a stage located on top of the base and is adapted to be operatively connected to a temperature control device, wherein the stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy to and from the temperature control device to the plurality of laboratory plate wells, and wherein the stage is adapted to be in contact with at least the bottom surface of each of the laboratory plate wells when the laboratory plate is placed on top of the portable temperature transfer device and covering the laboratory plate with an encasement comprising a thermally conductive material with cavity dimensions that will allow the enclosure of a standard laboratory plate. The temperature of the laboratory plate wells can be adjusted by controlling the temperature of the stage using the temperature control device.
In another embodiment of the present invention, a method is provided for culturing cells. The method comprises placing the cells on at least one of the wells of a laboratory plate comprising a plurality of wells, wherein the well further comprises a culture medium. The laboratory plate is then placed on a portable temperature transfer device, wherein the portable temperature transfer device comprises a base and a stage located on top of the base. The portable temperature transfer device is adapted to be operatively connected to a temperature control device, wherein the stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy to and from the temperature control device to the plurality of laboratory plate wells. The stage of the portable temperature transfer device is adapted to be in contact with at least the bottom surface of each of the laboratory plate well when the laboratory plate is placed on top of the portable temperature transfer device. The laboratory plate is covered with an encasement comprising a thermally conductive material with cavity dimensions that will allow the enclosure of a standard laboratory plate. The cells are cultured by adjusting the temperature of the laboratory plate wells by controlling the temperature of the stage using the temperature control device.
In another embodiment of the present invention, a method is provided for conducting chemical, binding, and molecular biological reactions, said method comprising placing assay components in at least one of the wells of a laboratory plate comprising a plurality of wells; placing the laboratory plate on a portable temperature transfer device, wherein the portable temperature transfer device comprises a base and a stage located on top of the base and is adapted to be operatively connected to a temperature control device, wherein the stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy to and from the temperature control device to the plurality of laboratory plate wells, and wherein the stage is adapted to be in contact with at least the bottom surface of each of the laboratory plate well when the laboratory plate is placed on top of the portable temperature transfer device; covering the laboratory plate with an encasement comprising a thermally conductive material with cavity dimensions that will allow the enclosure of a standard laboratory plate; and incubating the reaction assay by adjusting the temperature of the laboratory plate wells by controlling the temperature of the stage using the temperature control device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a feature-numbered illustration of the base and stage combination, the vault encasement and the assembled thermal vault. The stage in this illustration is designed to interface with round bottom plates.

FIG. 2 is an illustration showing a number-identified laboratory plate on top of the temperature transfer device of the invention with the open vault encasement above.

FIG. 3 is dimensional drawing of a thermal vault featuring a stage for round-bottom 96-well plates

FIG. 4 is a dimensional drawing of a thermal vault featuring a flat stage.

FIG. 5 is a dimensional drawing of the thermal vault encasement.

FIG. 6 is an illustration showing a P-trap gas exchange option of the invention, which enhances gas exchange with the exterior environment.

FIG. 7 is an illustration of-the exterior of a closed thermal vault featuring the gas exchange traps.

FIG. 8 is an illustration of a base that features an example of a gas exchange trap.

FIG. 9 is an illustration of a thermal vault device resting on an active heating and cooling device.

FIG. 10 is an illustration of a thermal vault device featuring a stage for round-bottom 96-well plates resting on a Biocision ThermalTray in a pan of ice.

FIG. 11 is a layout of an example of timing and temperature control (temperature control device) module for the thermal vault device.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides solutions for at least some of the drawbacks discussed above. Specifically, the present invention provides a portable temperature transfer device that is constructed from thermally conductive material and that by direct contact with the bottom of the wells of a laboratory plate provide an even well temperature across all wells of the plate. When used in combinations with a thermally conductive encasement, the device further provides for a dark and uniform gaseous and thermal environment immediately surrounding the laboratory plate. Due to the thermally conductive nature of the device, the device will also provide for uniform thermal transfer when the laboratory plate is undergoing thermal energy loss or gain from the surrounding environment. At least some of these and other objectives described herein will be met by embodiments of the present invention.
The present invention will be described with regard to the accompanying drawings which assist in illustrating various features of the invention. In this regard, the present invention generally relates to temperature transfer devices. That is, the invention relates to portable temperature transfer devices for use with laboratory plates. Generally the laboratory plates comprise a plurality of wells. Often these laboratory plates are commercially available in 6, 12, 24, 48, 96, or 384 well configurations, however, it should be appreciated that the scope of the invention is not limited to temperature transfer devices that are configured to be used with any particular number of wells in the laboratory plates.
The design of the thermal vault stage and encasement ensures rapid heat transfer between the thermal vault and multi-well laboratory plate. The large thermal mass acts as a capacitor to ensure that the laboratory plate rapidly equilibrates in temperature, whether warm or cold, with the thermal vault. As this equilibration takes place each of the wells in the laboratory plate undergoes substantially the same thermal history. Once equilibrated, the enclosed environment of the thermal vault protects the laboratory plate from transient environmental temperature changes such as moving the laboratory plate system from an incubator or ice bath to another location, or when incubator temperatures drop as a result of opening the incubator door. It also acts as an equilibration device when the entire system needs to be heated or cooled to a given temperature. By insulating the thermal vault upon removal from an environmental temperature source, such as an incubator or ice bath, the thermal vault also acts as a storage system such that a laboratory plate can be removed from an incubator, insulated, and transferred to another incubator at some later time without changes in the internal temperature of the laboratory plate wells.
Some of the features of the temperature transfer device of the invention are generally illustrated in FIGS. 1-11, which are provided for the purpose of illustrating the practice of the invention and which do not constitute limitations on the scope thereof.
As used herein, the terms “laboratory plates” and “cell culture plates” are generally used interchangeably, unless the context requires otherwise, to refer to various commercially available multi-welled plates that are adapted for use in culturing cells or tissues and various biological or chemical reaction assays. Laboratory plates are commercially readily available from a number of different sources including Fisher Scientific, Sigma, Aldrich, as well as other laboratory equipment suppliers.
In one aspect of the invention, a portable temperature transfer device is provided that typically comprising a base and a stage located on top of said base. The stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy from the temperature control device to the plurality of laboratory plate wells and is adapted to be in contact with at least the bottom surface of the laboratory plate wells when the laboratory plate is placed on top of said portable temperature transfer device.
Another aspect of the invention provides a portable temperature transfer device that comprises a base, a stage located on top of said base and an encasement that rests on the stage and encloses the stage. The stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy from the temperature control device to the plurality of laboratory plate wells and is adapted to be in contact with at least the bottom surface of the laboratory plate wells when the laboratory plate is placed on top of said portable temperature transfer device. The encasement fits into a groove that surrounds the perimeter of the stage such that when the laboratory encasement is placed on top of the stage, the stage prevents any significant lateral movement of the encasement relative to the base. The thermoconductive and insulated encasement will be in physical contact with the base and be in thermal equilibrium thereby providing a uniform temperature environment.
Referring to FIG. 1, the temperature transfer device, or Thermal Vault device, 100 generally comprises a base 104, a stage 108 and an optional encasement 112. The stage 108 can be a raised portion of base 104 or it can be a separate add-on to base 104. The top surface 300 of base 104 has height 204, width 208, and length 212. These dimensions are generally about 9 cm to about 18 cm, often about 1 cm to about 5 cm, more than the dimension of stage 108. It should be appreciated that the overall dimension of the temperature transfer device 100 is not these ranges or specific ranges disclosed herein. In general, the base dimension can vary significantly based on the particular application and place of use. The base 104 can comprise a flat bottom surface 216 as illustrated in FIG. 1, or it could comprise legs (not shown) similar to that of a typical table. However, it should be appreciated that the bottom surface 216 can be configured and designed in any manner as long as the bottom surface 216 provides a leveled stage 108. The level stage will ensure that the liquid in the wells has a uniform depth throughout the plate. The top surface 300 of stage 108 has height 304, width 308, and length 312. These dimensions are generally determined by the dimensions of the laboratory plate (see also FIGS. 3 and 4). As an example, a typical laboratory plate has dimensions of about 0.6 cm, 10.8 cm and 7.2 cm respectively.
The encasement 112 has a height 404, width 408 and a length 412 and are generally 2.2 cm by 15 cm by 11 cm respectively (see also FIG. 5). The encasement rim protrusion 416 will engage into recess 316 when the lid is in position.
In some embodiments of the instant invention, the area dimension of the stage is substantially identical to the area dimension of the bottom of the laboratory plate. In this manner, when the laboratory plate is placed on top of the stage, the stage prevents any significant lateral movement of the laboratory plate relative to the base.
Referring to FIG. 2, it can be seen that stage 108 is typically designed to fit snuggly with the laboratory plate 400 so that when coupled, the outside edges of the laboratory plate skirt receiver trough 318 (FIG. 1) restricts or prevents any lateral movement of the laboratory plate 400. The minimum height 304 of stage 108 (FIG. 1) is also often dictated by the amount of height needed to allow the top surface 300 to be in contact with the bottom of the wells of laboratory plate 400. The stage surface is configured for maximum surface to surface contact between the laboratory plate well bottom and the stage surface while minimizing the air gaps between the plate and stage. As an example, a laboratory plate with round bottom wells will have maximum contact with a plate in which the stage has hemispherical indentations to receive the round bottom well profile as in FIGS. 1 and 2. In some instances, this may require specialized recesses to accommodate casting sprues, flashings or other features specific to a particular manufacturer.
Thus, unlike a completely flat heat sink surface which leaves an insulating air gap between the well bottom of the laboratory plate and the heat sink surface, the raised stage design of the temperature transfer device of the invention provides a direct contact with the well bottom of the laboratory plate. The raised stage of the temperature transfer device has an added advantage of restricting or preventing lateral movement of the laboratory plate during its use, e.g., the laboratory process. The material from which the temperature transfer device is constructed allows rapid heat exchange so that the desired temperature range can be quickly established by contact with a thermal mass such as ice, dry ice, liquid nitrogen or any other cooling device, a water bath or a hot plate or any other heating device.
The base typically comprises a thermo-conductive material. In some embodiments, the thermo-conductive material comprises a thermo-conductive metal. Within these embodiments, in some instances the thermo-conductive metal comprises aluminum, copper, aluminum alloy, copper alloy, or a combination thereof. In some embodiments, the portable temperature transfer device has attached insulating feet.
The stage is also typically comprised of a thermo-conductive material such as aluminum, aluminum alloy, copper, copper alloy, and other materials (both metal and non-metal) that are known to be good thermo conductors. And as stated above and depicted in FIG. 1, the temperature transfer device 100 is designed with a raised stage 108 upon which the laboratory plate 400 rests. The raised stage design restricts the lateral movement of any laboratory plate and allows the bottom of the laboratory plate 400 to be in direct contact with the temperature transfer device. This design provides efficient heat transfer between the laboratory plate 400 and the temperature transfer device 100 while preventing any substantial lateral movement of the laboratory plate 400 during use.
In some embodiments, the top surface 300 of stage 108 further comprises a plurality of concavities (FIGS. 1 and 2) such that the individual wells of laboratory plate sits within the concavity. Each concavity is generally adapted to fit at least a portion of an individual laboratory plate well, or protrusions from the plate bottom surface. In this manner at least a portion of the sidewalls of the wells are also in contact with the portable temperature transfer device. Often such a configuration allows faster and/or better thermal energy transfer to/from the laboratory plate well. As can be appreciated, the more surface area contact between individual wells of the laboratory plate and the stage (via its concavity (not shown) and/or top surface 300) will lead to faster heat transfer. Plate bottom geometry examples include flat bottom, rounded-bottom wells, V-bottom wells and, truncated-conical bottom wells. The dimensions of a stage designed to accept a round bottom plate are shown in FIG. 3. FIG. 4 provides the dimensions of a stage designed to accept a flat bottom plate.
The thermal vault is an assembly that consists of a base as described above and an aluminum encasement that will entirely cover a laboratory plate resting on the base. The encasement has internal dimensions such that when resting upon the base, there is an internal space sufficient to enclose the plate without direct contact. The encasement has a rim protrusion around the rim in contact with the base that fits into a groove in the base that restricts the lateral movement of the encasement and prevents slippage. In addition, the groove into which the encasement rim protrusions fit may be filled with water or buffer to enable gas exchange while maintaining the level of humidity in the interior of the assembly. The shoulder of the rim base of the encasement is in direct contact with the base, to achieve rapid thermal equilibrium with the base.
In some embodiments, the device contains liquid traps under the encasement rim which facilitate gas exchange with the environment and the device interior by gas exchange through the liquid in the trap thereby allowing gas exchange to occur while at the same time isolating the gaseous contents of the device interior through the presence of a liquid seal (FIGS. 6-8).
In other embodiments, the encasement of the portable temperature transfer device contains slots to allow gas exchange while maintaining light-safe protection. The encasement may contain a plurality of ports, vents, slits, filters, membranes, and perforations to enhance gas exchange with the exterior of the assembly. The degree of gas exchange would be adjusted to create the optimal balance of thermal regulation and gas content of the assembly interior.
The encasement of the thermal vault is typically made from a thermally conductive material such as aluminum, aluminum alloys, copper, copper allows, etc. The encasement has internal dimensions such that when resting upon the base, there is a space that is sufficient to enclose the plate without direct contact. The encasement has a rim protrusion around the rim in contact with the base that fits into a groove in the base that restricts the lateral movement of the encasement and prevents slippage. The upper surface of the encasement may be vaulted to allow condensed liquids and adherent drops on the encasement interior surface to drain to the side of the plate without falling onto or into the plate. The dimensions of an example of the encasement can be seen in FIG. 5. In some embodiments the encasement will be surrounded by a foam exterior to reduce heat exchange with the environment.
The base consists of a central stage that is in direct contact with the bottom of the wells of the plate. A groove relief in the base surrounds the stage and provides a space in which the rim or skirt of the laboratory plate can extend without coming into direct contact with the base material. Surrounding the groove relief is a secondary groove into which he encasement rim is received. The depth of the encasement groove can be greater than the depth of the rim protrusion so that when the encasement groove is filled partially with liquid, a liquid seal is formed around the encasement and base interface. The encasement groove may feature a plurality of side extensions on both sides of the groove to facilitate gas exchange through the liquid seal (see FIGS. 6-8).
In various embodiments of the present invention, the stage is adapted to be operatively connected to a temperature control device. In some embodiments, the temperature control device 100 can comprise a coil (not shown) that cools or heats the stage 108. Such coil can be placed on the bottom surface of stage 108, i.e., underneath stage 108 such that the coil does not come in direct contact with the laboratory plate. Additional examples of temperature control include an ice bath, block heaters, water baths, refrigerators, incubators, warm/cold-rooms, freezers, solid-state coolers, chemical reaction heaters, open flames heaters, heating pads, and chemical reaction coolers (see FIGS. 9 and 10). Any temperature control coils that can heat or cool, which are well known in the art, can be used as long as the temperature of the coil can be transferred to the stage 108.
In another embodiment of the invention, the Thermal Vault device can be used in conjunction with the Biocision ThermalTray in a water- or ice-bath. The Thermal Vault device would rest on the ThermalTray surface and quickly achieve thermal equilibrium with the ThermalTray (FIG. 10). An alternative for this temperature control device would be a warm plate or even crushed ice in a pan (see FIGS. 9 and 10).
Often non-electronic temperature control devices, such as an ice-bath, ice, dry ice, liquid nitrogen, or other cold solids or liquids, are placed underneath the temperature transfer device 100 such that any moisture it creates is contained within the environment enclosed by the base 104. In this manner, temperature transfer device 100 prevents or substantially reduces any undesired humidity from reaching the individual wells of laboratory plates.
The temperature control device can be operated to provide a constant stage and laboratory plate temperature or can be used to increase or decrease the temperature of the stage and laboratory plate. In a temperature changing capacity, the temperature control device would be capable of laboratory plate temperature change rates of, but not limited to 0 degrees per second to 5 degrees per second. In some embodiments, the temperature of the stage is adjusted and the temperature transfer device is used as a stand alone heat reservoir or heat sink.
In other embodiments, the temperature control device comprises a temperature control system for controlling the temperature of said stage (FIG. 11). The temperature control device may comprise a timer control system, a central processing unit and/or a programmable unit for automatically adjusting the temperature setting, time setting, or a combination thereof of the stage. Such systems allow one to set the desired temperature and/or time to allow automated operation. In some instances, a central processing unit (e.g., a computer) can be used as the control system(s). Both the temperature control system and timer control system are well known in the art and can be configured to be used with the temperature control device. In some embodiments, the temperature control device is removably attached to the temperature transfer device.
Although the primary purpose of the device is to provide identical thermal, gaseous and well volume history of the laboratory plate, the temperature modification and thermal energy exchange of the plate with the environment remains as a potential feature of the plate history, therefore the following information may be directly relevant. The portable temperature control device described below refers to the base and stage of the thermal vault in this case.
Another aspect of the invention provides a method for adjusting temperature of a laboratory plate, which comprises a plurality of wells. The method generally comprises placing the laboratory plate on a portable temperature transfer device, wherein the portable temperature transfer device comprises a base and a stage located on top of the base and is adapted to be operatively connected to a temperature control device, wherein the stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy to and from the temperature control device to the plurality of laboratory plate wells, and wherein the stage is adapted to be in contact with at least the bottom surface of each of the laboratory plate wells when the laboratory plate is placed on top of the portable temperature transfer device and using an encasement comprising a thermally conductive material with cavity dimensions that allow the enclosure of the laboratory plate. The temperature of the laboratory plate wells can be adjusted by controlling the temperature of the stage using the temperature control device. The enclosed environment of the thermal vault protects the laboratory plate from transient environmental temperature changes and acts as an equilibration device when the entire system needs to be heated or cooled to a given temperature.
In some embodiments, the temperature control device is removably attached to the temperature transfer device. Yet in other embodiments, the temperature control device comprises a heating element, a cooling element, or a combination thereof. Still in other embodiments, the temperature of the stage is controlled prior to placing the laboratory plate on the portable temperature transfer device.
Another aspect of the invention provides a method for culturing cells, said method comprising: placing the cell on at least one of the wells of a laboratory plate comprising a plurality of wells, wherein the well further comprises a culture medium; placing the laboratory plate on a portable temperature transfer device, wherein the portable temperature transfer device comprises: a base; and a stage located on top of the base and is adapted to be operatively connected to a temperature control device, wherein the stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy to and from the temperature control device to the plurality of laboratory plate wells, and wherein the stage is adapted to be in contact with at least the bottom surface of each of the laboratory plate well when the laboratory plate is placed on top of the portable temperature transfer device and using an encasement comprising a thermally conductive material with cavity dimensions that allow the enclosure of the laboratory plate. This allows one to optimize cell culturing conditions by adjusting the temperature of the laboratory plate wells by controlling the temperature of the stage using the temperature control device.
Yet another aspect of the invention provides a method for conducting chemical, binding, and molecular biological reactions, said method comprising placing assay components in at least one of the wells of a laboratory plate comprising a plurality of wells; placing the laboratory plate on a portable temperature transfer device, wherein the portable temperature transfer device comprises a base and a stage located on top of the base and is adapted to be operatively connected to a temperature control device, wherein the stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy to and from the temperature control device to the plurality of laboratory plate wells, and wherein the stage is adapted to be in contact with at least the bottom surface of each of the laboratory plate well when the laboratory plate is placed on top of the portable temperature transfer device; covering the laboratory plate with an encasement comprising a thermally conductive material with cavity dimensions that will allow the enclosure of a standard laboratory plate; and incubating the reaction assay by adjusting the temperature of the laboratory plate wells by controlling the temperature of the stage using the temperature control device.
In summary, the temperature transfer device of the instant invention can be used for any application in which it is desired to control the thermal distribution and thermal history of a laboratory plate (e.g. 384, 96, 48, 24, 12 or 6 well plate) and substantially maintain the temperature for extended periods of time. The temperature transfer device can be used in applications that depend upon temperature stabilization of, or efficient-heat transfer to or from laboratory plates.

EXAMPLE 1

As an example, mammalian cell agar assays depend on rapid cooling of a cell suspension in molten agar so that the agar solidifies before the cells have a time to settle. In this particular application, the temperature transfer device is cooled to a desired temperature and the laboratory plate is placed on top of the stage such that the top surface of the stage comes in direct contact with the bottom of individual wells of the laboratory plate. This allows the contents of the individual wells to be cooled such that the agar solidifies before the cells have a time to settle.
Typically, the temperature transfer device of the invention is placed on ice, dry ice, liquid nitrogen or any heating or cooling device until the temperature of the temperature transfer device has reached the approximate temperature of the cooling or heating medium. The temperature transfer device can be left in contact with the cooling or heating medium or placed on a thermally insulating surface such as plastic foam board or rubber mat. Alternatively, the temperature transfer device can have attached insulating feet. The bottom of the laboratory plate is then placed in contact with the pedestal stage (i.e., top surface) of the temperature transfer device. The laboratory or cell culture plate are rapidly cooled or warmed and held at equilibrium temperature without permanent physical change to the laboratory plate material.

EXAMPLE 2

Reduction of Edge Effects in Cell Culture
A thermal vault with the sterile culture plate and plate cover seated in place would be placed into an incubator and allowed to equilibrate with the interior temperature. During this interval, cultured cells would be removed from their primary culture vessel by use of trypsin solution, transferred to a centrifuge tube, concentrated by centrifugation, and re-suspended in warm growth medium. The thermal vault with culture plate would be retrieved from the incubator and the cells to be cultured would be quickly dispensed to the appropriate wells. The plate cover would be replaced and the thermal vault encasement be placed into position. The assembly would be returned to the incubator and allowed to remain undisturbed until the cells have attached or until any other experimental way point. Due to the thermally conductive property of the stage, this method/procedure allows the culture plate to maintain a uniform well temperature across the plate while at the same time maintaining a uniform temperature within each individual well. The vault encasement will assist in the distribution of the thermal energy in the base to the vault interior thereby reducing the temperature differential between the bottom and top of the laboratory plate. The uniform well bottom temperature and the reduction in the temperature differential between the top and bottom of the plate will reduce the convective swirling and circulation of the liquid within the well thereby reducing or preventing deposition of the cells to one side of the well and allowing even settling and growth of the cells on the well bottom.

EXAMPLE 3

Reduction of Edge Effects in ELISA Assays
For reduction of edge effects in an ELISA assay, a 96-well flat bottom plate would be placed onto a thermal vault base either in a stand-alone configuration or in thermal contact with a temperature-regulation device. A standard ELISA assay would be assembled into the wells of the 96-well plate, and the plate cover replaced or the plate sealed using commonly available adhesive closure seals. The thermal vault encasement would be placed over the 96-well plate and seated into the base groove. A standard reaction time would be allowed to pass while the plate is either allowed to remain still or agitated by a common shaking device. The ELISA assay would then be completed by application of the appropriate wash steps and colorimetric reaction while the plate remains in contact with the vault base. Due to the thermally conductive property of the stage, a uniform well temperature would be maintained across the plate thereby reducing or eliminating temperature-dependent differences in binding kinetics between well. A similar benefit of temperature uniformity would be obtained from the vault encasement as it would distribute thermal energy from the base, creating a uniform vault interior temperature and thereby reducing or eliminating any temperature differential between the bottom and the top of the plate.

EXAMPLE 4

Reduction of Edge Effects in Enzymatic Reactions
As another example of the use of the device, a 96-well flat bottom plate would be placed onto a thermal vault base either in a stand-alone configuration or in thermal contact with a temperature-regulation device. A solution containing enzymatic reaction components would be introduced into the plate wells, the plate cover replaced and the thermal vault encasement seated on the base. Following the appropriate incubation interval, the progress of the reaction would be monitored by the appropriate read-out method.
The foregoing discussion of the invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. Although the description of the invention has included description of one or more embodiments and certain variations and modifications, other variations and modifications are within the scope of the invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.

Claims

1. A portable temperature transfer device for transferring thermal energy to and from a laboratory plate comprising a plurality of wells, said portable temperature transfer device comprising:

a base;

a stage located on top of said base, wherein said stage comprises a thermo-conductive material adapted for transferring thermal energy from a temperature control device to the plurality of laboratory plate wells, and wherein said stage is adapted to be in contact with at least the bottom surface of the laboratory plate wells when the laboratory plate is placed on top of said portable temperature transfer device; and

an encasement comprising a thermally conductive material with cavity dimensions that will allow the enclosure of standard laboratory plates.

2. The portable temperature transfer device of claim 1; wherein the stage surface is contoured in a manner such that there is maximum contact with the bottom surface of the laboratory plate thereby insuring optimal thermal exchange with the stage and base, thereby providing optimally identical thermal history in all of the plate wells during the interval of interest.

3. The portable temperature transfer device of claim 1; wherein the base has a recess introduced that will receive an encasement rim protrusion.

4. The portable temperature transfer device of claim 3; wherein the encasement has attached a rim protrusion that will fit into the matching recess in the base.

5. The portable temperature transfer device of claim 3; wherein the base recess is designed to contain liquids that will form a seal to prevent direct gas exchange of the vault interior.

6. The portable temperature transfer device of claim 3; wherein the base recess includes lateral excavations of the base that will extend a liquid seal beyond the base area occupied by the encasement interface.

7. The portable temperature transfer device of claim 1; wherein the encasement has ports, slits, conduits, membranes, filters, or perforations that allow controlled gas exchange between the vault interior and the immediate environment surrounding the encasement.

8. The portable temperature transfer device of claim 1, wherein the stage is adapted to be operatively connected to a temperature control device.

9. The portable temperature transfer device of claim 1, wherein said thermo-conductive material comprises a thermo-conductive metal.

10. The portable temperature transfer device of claim 9, wherein said thermo-conductive metal comprises aluminum, copper, aluminum alloy, copper alloy, or a combination thereof.

11. The portable temperature transfer device of claim 1, wherein said stage further comprises a plurality of concavities, and wherein each concavity is adapted to fit at least a portion of individual laboratory plate well.

12. The portable temperature transfer device of claim 1, wherein the temperature control device comprises a temperature control system for controlling the temperature of said stage.

13. The portable temperature transfer device of claim 1, wherein said temperature control device comprises a timer control system.

14. The portable temperature transfer device of claim 1, wherein said temperature control device comprises a central processing unit.

15. The portable temperature transfer device of claim 1, wherein said temperature control device comprises a programmable unit for automatically adjusting the temperature setting, time setting, or a combination thereof of said stage.

16. The portable temperature transfer device of claim 1, wherein said temperature control device is removably attached to said temperature transfer device.

17. The portable temperature transfer device of claim 1, wherein said base comprises a thermo-conductive material.

18. The portable temperature transfer device of claim 1, wherein the area dimension of the stage is substantially identical to the area dimension of the bottom of the laboratory plate such that when the laboratory plate is placed on top of the stage, the stage prevents any significant lateral movement of the laboratory plate relative to the base.

19. The portable temperature transfer device of claim 1, wherein said temperature transfer device has attached insulating feet.

20. The portable temperature transfer device of claim 1, wherein the encasement fits into a groove etched around the perimeter of the stage such that when the laboratory encasement is placed on top of the stage, the stage prevents any significant lateral movement of the encasement relative to the base.

21. The portable temperature transfer device of claim 1, wherein the encasement has a foam exterior to reduce heat exchange with the environment.

22. A method for adjusting temperature of a laboratory plate comprising a plurality of wells, said method comprising:

placing the laboratory plate on a portable temperature transfer device, wherein the portable temperature transfer device comprises a base and a stage located on top of the base and is adapted to be operatively connected to a temperature control device, wherein the stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy to and from the temperature control device to the plurality of laboratory plate wells, and between the wells, and wherein the stage is adapted to be in contact with at least the bottom surface of each of the laboratory plate well when the laboratory plate is placed on top of the portable temperature transfer device;

covering the laboratory plate with an encasement comprising a thermally conductive material with cavity dimensions that will allow the enclosure of a standard laboratory plate; and

adjusting the temperature of the laboratory plate wells by controlling the temperature of the stage using the temperature control device.

23. The method of claim 22, wherein the temperature control device is removably attached to the temperature transfer device.

24. The method of claim 22, wherein the temperature control device comprises a heating element, a cooling element, or a combination thereof.

25. The method of claim 22, wherein the temperature of the stage is adjusted prior to placing the laboratory plate on the portable temperature transfer device.

26. A method for culturing cells, said method comprising:

placing the cell on at least one of the wells of a laboratory plate comprising a plurality of wells, wherein the well further comprises a culture medium;

placing the laboratory plate on a portable temperature transfer device, wherein the portable temperature transfer device comprises a base and a stage located on top of the base and is adapted to be operatively connected to a temperature control device, wherein the stage comprises a thermo-conductive material adapted for rapidly transferring thermal energy to and from the temperature control device to the plurality of laboratory plate wells, and wherein the stage is adapted to be in contact with at least the bottom surface of each of the laboratory plate well when the laboratory plate is placed on top of the portable temperature transfer device;

culturing the cells by adjusting the temperature of the laboratory plate wells by controlling the temperature of the stage using the temperature control device.

27. The method of claim 26, wherein the temperature control device is removably attached to the temperature transfer device.

28. The method of claim 26, wherein the temperature control device comprises a heating element, a cooling element, or a combination thereof.

29. The method of claim 26, wherein the temperature of the stage is adjusted prior to placing the laboratory plate on the portable temperature transfer device.

30. A method for conducting chemical, binding, and molecular biological reactions, said method comprising:

placing assay components in at least one of the wells of a laboratory plate comprising a plurality of wells;

incubating the reaction assay by adjusting the temperature of the laboratory plate wells by controlling the temperature of the stage using the temperature control device.

31. The method of claim 30, wherein the temperature control device is removably attached to the temperature transfer device.

32. The method of claim 30, wherein the temperature control device comprises a heating element, a cooling element, or a combination thereof.

33. The method of claim 30, wherein the temperature of the stage is adjusted prior to placing the laboratory plate on the portable temperature transfer device.