Sample Block Apparatus and Method for Maintaining a Microcard on a Sample Block
A sample block apparatus for a thermal cycler is provided, which can be configured for use with a microcard containing a plurality of samples of biological material. The apparatus can comprise a sample block comprising an upper surface configured for resting a microcard thereon. The upper surface can include surface irregularities for defining spaces between the surface irregularities and a microcard that may be positioned thereon. The apparatus can include a vacuum source in fluid communication with the space between the surface irregularity and the microcard positioned thereon. The vacuum source can be configured to create a substantial vacuum in the spaces thereby imparting a force on the microcard to retain the microcard on the sample block upper surface. The sample block apparatus can also include a temperature control system operatively connected with the sample block to cycle the sample block according to a user-defined profile.
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This application is a continuation of U.S. patent application Ser. No. 10/207,263 filed on Jul. 30, 2002. The entire disclosure of the above application is incorporated herein by reference.
FIELDThe present teachings relate generally to sample block apparatus suitable for use in a thermal cycling device, and methods of maintaining a microcard on a sample block of a thermal cycling device. More particularly, the present teachings further relate, in various aspects, to sample block apparatus utilizing a vacuum to maintain a microcard on a sample block during a nucleic acid amplification process such as polymerase chain reaction (PCR).
BACKGROUNDBiological testing has become an important tool in detecting and monitoring diseases. In the biological testing field, thermal cycling is used to amplify nucleic acids by, for example, performing PCR and other reactions. PCR in particular has become a valuable research tool with applications such as cloning, analysis of genetic expression, DNA sequencing, and drug discovery.
Recent developments in the field have spurred growth in the number of tests that are performed. One method for increasing the information obtainable through such biological testing is to provide real-time detection capability during thermal cycling. During real-time detection the characteristics of samples of biological materials can be detected while the sample well tray remains positioned in the thermal cycling device. A method for increasing throughput is to place a large number of samples on a single microcard. In this manner, more tests may be performed in a given period of time. Moreover, it is possible to reduce costs by running at low reaction volumes of biological materials. It may also be desirable for there to be substantial temperature uniformity between the plurality of samples on a single microcard.
SUMMARYVarious aspects generally relate to, among other things, a thermal cycling device for thermal cycling samples of biological material contained in a microcard.
Various aspects provide a thermal cycling device for thermally cycling samples of biological material contained in a microcard having a top and bottom surface. The thermal cycling device can comprise a sample block having an upper surface configured for engaging the bottom surface of a microcard, a vacuum device, and a temperature control system operatively connected with the sample block. The upper surface of the sample block may include a plurality of channels, the channels defining spaces between the sample block and the bottom surface of a microcard that may be positioned thereon. The vacuum device may be in fluid communication with the sample block for drawing gas out of the spaces defined by the channels in the sample block. The vacuum device may be configured for substantially maintaining a vacuum between the sample block and microcard so that a retention force is imparted on the microcard to urge the microcard toward the sample block. The temperature control system may be configured for cycling the sample block through a sequence of times and temperatures comprising at least a first temperature maintained for a first period of time and a second temperature maintained for a second period of time, with the second temperature being higher than the first temperature, and the cycling comprising at least two repetitions of said sequence of time and temperatures.
Various other aspects comprise a sample block apparatus for a thermal cycler configured for use with a microcard containing a plurality of samples of biological material. The sample block apparatus can comprise a sample block, a vacuum source, and a temperature control system operatively connected with the sample block to cycle the sample block according to a user-defined profile. The sample block can comprise an upper surface configured for resting a microcard thereon, the upper surface including surface irregularities for defining spaces between the surface irregularities and a microcard that may be positioned thereon. The vacuum source may be in fluid communication with the space between the surface irregularity and the microcard positioned thereon. The vacuum source may be configured to create a substantial vacuum in the spaces thereby imparting a force on the microcard to retain the microcard on the sample block upper surface.
Further various aspects comprise a microcard retaining apparatus for a thermal cycler of biological materials. The microcard retaining apparatus can comprise a sample block having a an upper surface and a vacuum port. The sample block upper surface may be substantially flat and configured to engage a bottom surface of a microcard that may be positioned thereon. The upper surface of the sample block may further comprise a plurality of recesses. The vacuum port in the sample block may be in fluid communication with the plurality of recesses to assist in imparting a vacuum in the recesses to cause the microcard to press downward against the upper surface of the sample block. The vacuum port may be configured for attachment to a vacuum source.
Various aspects also comprise a method of maintaining a microcard on a sample block of a thermal cycling device. The method can include the steps of providing a sample block with a plurality of channels on an upper surface thereof. The method may further include the step of providing a space for a microcard containing at least one sample of biological material above the upper surface of the sample block so that a bottom surface of the microcard may contact the upper surface of the sample block. A vacuum may be imparted on the spaces defined by the channels on the upper surface of the sample block and the bottom surface of the microcard positioned adjacent the upper surface of the sample block, the vacuum creating a force to urge the microcard against the upper surface of the sample block. The microcard may then be thermally cycled through a sequence of times and temperatures comprising at least a first temperature maintained for a first period of time and a second temperature maintained for a second period of time, with said second temperature being higher than said first temperature. Optionally, simultaneously with the step of thermally cycling the microcard, the optical characteristics of the at least one sample of biological material may be detected.
Further various aspects comprise an apparatus for thermally cycling samples of biological material contained in a microcard. The apparatus can comprise a sample block configured to assist in heating and cooling a microcard during thermal cycling, means for urging a microcard against a top surface of a sample block of a thermal cycling device using a vacuum, and means for imposing a substantial vacuum in a space between the sample block and the microcard.
Still further various aspects comprise a thermal cycling apparatus. The thermal cycling apparatus can comprise a base, with said base defining a void therein, a vacuum port disposed for fluid communication with the void, support features disposed adjacent the void on the base, and a temperature control system. The support features include uppermost surface regions defining a common plane. The temperature control system may be configured for cycling at least one of the base and the support features through a sequence of times and temperatures comprising at least a first temperature maintained for a first period of time and a second temperature maintained for a second period of time, with said second temperature being higher than said first temperature and said cycling comprising at least two repetitions of said sequence of times and temperatures.
It is to be understood that both the foregoing general description and the following description of various embodiments are exemplary and explanatory only and are not restrictive.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several exemplary embodiments. In the drawings,
Reference will now be made to various exemplary embodiments, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
In accordance with various embodiments, a thermal cycling device is provided. In various aspects, the thermal cycling device may perform nucleic acid amplification on a plurality of biological samples positioned in a microcard. In various embodiments, the thermal cycling device includes a sample block. In various embodiments, the thermal cycling device may also include a microcard carrier and a cover. Various embodiments are directed toward a sample block apparatus comprising a sample block, a vacuum source, and a temperature control system.
Although terms like “horizontal,” “vertical,” “upward,” and “downward” may be used in describing various aspects of the present teachings, it should be understood that such terms are for purposes of more easily describing the teachings, and do not limit the scope of the teachings.
In various embodiments, such as illustrated in
In various embodiments, the thermal cycling device performs real-time detection of the nucleic acid amplification of the samples in the microcard during thermal cycling. Real-time optical detection systems are known in the art, as also described in greater detail in, for example, U.S. Pat. Nos. 5,928,907 and 6,015,674 to Woudenberg et al., incorporated herein above. During real-time detection, various characteristics of the samples are detected during the thermal cycling in a manner known in the art. Real-time detection permits more accurate and efficient detection and monitoring of the samples during the nucleic acid amplification. In the embodiment shown in
The thermal cycling device 10 shown in
As embodied herein and shown in
In the embodiment shown in
In accordance with various embodiments, the thermal cycling device includes a sample block apparatus configured to receive the microcard thereon. As described herein and shown in
Sample block platform 34 comprises a raised upper region with a top surface 52, and a support 37. The support 37 includes a flat upper surface 38 and angled support member 39. In the embodiment shown, the sample block platform may be removably attached to the sample block base 32 via a fastening member 42. In the example shown, the fastening member 42 is a threaded fastener. Any other type of fastening member may also be suitable. In other embodiments, the sample block platform may be integral with the sample block base 32.
The sample block base 32 and sample block platform 34 may be made out of any suitable material, such as aluminum, gold-plated silver, or a thermally-conductive polymer/plastic. The material can be heat conductive so that the sample block may assist in thermal cycling. The sample block base 32 may be attached to any known type of heat sink. In the embodiment shown in
The sample block may be operatively connected to a temperature control system programmed to raise and lower the temperature of the sample block according to a user-defined profile. Several non-limiting examples of suitable temperature control systems for raising and lowering the temperature of the sample block are described in U.S. Pat. No. 5,656,493 to Mullis et al. and U.S. Pat. No. 5,475,610 to Atwood et al., the disclosures of which are both hereby incorporated by reference for any purpose. For example, in various embodiments, a user supplies data defining time and temperature parameters of the desired PCR protocol to a control computer that causes a central processing unit (CPU) of the temperature control system to control thermal cycling of the sample block. In a typical thermal cycler of the present teachings, the temperature control system may be configured for cycling the sample block through a sequence of times and temperatures comprising at least a first temperature maintained for a first period of time and a second temperature maintained for a second period of time, with the second temperature being higher than the first temperature, and the cycling comprising at least two repetitions of said sequence of time and temperatures.
In accordance with various embodiments, the sample block comprises an upper surface configured for resting a microcard thereon during thermal cycling of the microcard. The upper surface includes surface irregularities for defining a space between selected regions of the upper surface and a microcard positioned thereon during thermal cycling. In various embodiments, the surface irregularities comprise channels or recesses. As embodied herein, and shown in
Although
The channels (or recesses or voids) may be formed in the upper surface 52 by any known manner. The width and depth of the channels may be varied from that shown in
In various embodiments, the sample block apparatus further includes a vacuum device in fluid communication with the sample block platform for drawing gas, such as air, out of the spaces defined by the channels in the sample block platform. The vacuum device is configured for substantially maintaining a vacuum between the sample block platform and microcard so that a downward force is imparted on the microcard to urge the microcard toward the sample block platform. The vacuum device may be connected to the sample block via a vacuum port positioned on or in the sample block platform. In the embodiment of
Moreover, in real-time detection apparatuses, it may be desirable to minimize the amount of structure located between the microcard and the optical detection system. In various embodiments, the provision of the vacuum in the spaces under the microcard eliminates the need for an apparatus such as a plate positioned above the microcard that presses against the upper surface in the spaces between the sample chambers. By eliminating the need for such a pressing plate, it may be possible to utilize a greater portion of the upper surface for sample chambers. If a pressing plate is not used, space does not need to be reserved for pressing on the upper surface of the microcard. It may be desirable that there is a sufficient initial downward force on the microcard so that an initial vacuum can be drawn.
It should be understood that the channels 54 and 56 shown in
In various embodiments, the sample block platform may further include a groove positioned around the outer periphery of the sample block platform channels. In the exemplary embodiment shown in
In accordance with various embodiments, the thermal cycling device may also include a microcard carrier. As described herein and shown in
In the embodiment shown in
The microcard carrier 70 may also include a pair of guide members 76 for engagement with the notches 20 that may be provided in the microcard 12. The guide members 76 and notches 20 may assist in preventing horizontal movement between the microcard and the microcard carrier. In various embodiments, the microcard and microcard carrier may snap-fit together. It should be understood that the guide members and notches are optional.
In various embodiments, the thermal cycling device may also comprise a cover.
In various embodiments, a seal can be maintained between microcard 12 and sample block platform 34 without a microcard carrier and cover. This can be true, for example, when the microcard carrier has a high rigidity. A rigid microcard may tend to be more resistant to warping than a flexible microcard, and therefore may be able to maintain a seal with the gasket without any external force (such as a microcard carrier) pressing downward on it. If the microcard is very flexible and prone to warping, it may be helpful to provide some type of device for pressing downward on the microcard in the area adjacent the gasket.
An operation of the thermal cycling device for the embodiment of
Next, a vacuum source is attached to a vacuum port on the side of the sample block so that any air positioned in the spaces defined by channels 54 and 56 and a bottom surface 16 of the microcard is evacuated. When the space is at a substantial vacuum, the microcard will be pulled downward by the vacuum so that the microcard is firmly pressed against the top flat surface 52 of the sample block platform 34. In this manner, no large forces are needed on the top central portion of the microcard and substantial temperature uniformity across the sample chambers may be achieved, if desired. Thermal cycling of the apparatus may now be performed, with or without real-time detection by the optical detection system. During thermal cycling, the temperature control system of the thermal cycling device is operatively connected to the sample block to cause the temperature of the sample block to raise and lower according to a pre-programmed protocol. In one embodiment, the sample block (and microcard) are thermally cycled through a sequence of times and temperatures comprising at least a first temperature maintained for a first period of time and a second temperature maintained for a second period of time. The second temperature is higher than the first temperature. The thermal cycling includes at least two repetitions of the sequence of time and temperatures. After the thermal cycling is completed, the microcard and microcard carrier may then be removed.
Further various embodiments of the thermal cycling device contemplate structure such as shown in
The operation of the thermal cycling device for the embodiment of
The embodiment of
As shown in
The thermal cycling device of
As is clear from the above descriptions of various embodiments, the present teachings include a method of maintaining a microcard on a sample block of a thermal cycling device. The method can include the steps of providing a sample block with a plurality of channels on an upper surface thereof. The method may further include the step of providing a space above the upper surface of the sample block for a microcard containing at least one sample of biological material so that a bottom surface of the microcard may contact the upper surface of the sample block. A vacuum may then be imparted on the spaces defined by the channels on the upper surface of the sample block and the bottom surface of the microcard positioned adjacent the upper surface of the sample block, the vacuum creating a force to urge the adjacent microcard against the upper surface of the sample block. The microcard may then be thermally cycled through a sequence of times and temperatures comprising at least a first temperature maintained for a first period of time and a second temperature maintained for a second period of time, with said second temperature being higher than said first temperature. Simultaneously with the step of thermally cycling the microcard, the optical characteristics of the at least one sample of biological material or of one or more detectable markers associated therewith may be detected. In accordance with various embodiments, a gasket may be provided on an outer peripheral surface of the sample block, the gasket contacting and forming a seal with the bottom surface of the microcard during thermal cycling of the microcard.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure and methods described above. Thus, it should be understood that the present teachings are not limited to the examples discussed in the specification. Rather, the present teachings are intended to cover modifications and variations.
Claims
1-9. (canceled)
10. A sample block apparatus for a thermal cycler configured for use with a microcard containing a plurality of samples of biological material, comprising:
- a sample block comprising an upper surface configured for resting a microcard thereon, the upper surface including surface irregularities for defining spaces between the surface irregularities and a microcard that may be positioned thereon;
- a vacuum source in fluid communication with the space between the surface irregularity and the microcard positioned thereon, the vacuum source being configured to create a substantial vacuum in the spaces thereby imparting a force on the microcard to retain the microcard on the sample block upper surface; and
- a temperature control system operatively connected with the sample block to cycle the sample block according to a user-defined profile.
11. The sample block apparatus of claim 10, wherein the surface irregularities on the upper surface of the sample block comprise channels.
12. The sample block apparatus of claim 11, wherein the channels comprise a plurality of perpendicularly intersecting grooves on the upper surface of the sample block.
13. The sample block apparatus of claim 12, wherein the grooves are positioned in such a manner that the grooves are not positioned immediately vertically below the chambers in the microcard.
14. The sample block apparatus of claim 11, wherein the channels comprise a plurality of substantially parallel grooves on the upper surface of the sample block.
15. The sample block apparatus of claim 12, wherein the grooves are positioned in such a manner that the channels are not positioned immediately vertically below the chambers in the microcard.
16. The sample block apparatus of claim 10, wherein the surface irregularities on the upper surface of the sample block comprise rough surfaces.
17. The sample block apparatus of claim 11, wherein the sample block further comprises a gasket positioned around an outer periphery of the sample block channels, the gasket configured to engage a bottom surface of the microcard when the microcard is positioned on the sample block.
18. The sample block apparatus of claim 17, wherein the sample block further comprises a groove around the outer periphery of the channels, the gasket being positioned in the groove.
19. The sample block apparatus of claim 10, wherein the user-defined profile of the temperature control system is defined by a sequence of times and temperatures comprising at least a first temperature maintained for a first period of time and a second temperature maintained for a second period of time, with said second temperature being higher than said first temperature, and said cycling comprising at least two repetitions of said sequence of time and temperatures.
20. A method of maintaining a microcard on a sample block of a thermal cycling device, comprising:
- providing a sample block with a plurality of channels on an upper surface thereof;
- providing a microcard containing at least one sample of biological material above the upper surface of the sample block so that a bottom surface of the microcard may contact the upper surface of the sample block;
- imparting a vacuum on spaces defined by the channels on the upper surface of the sample block and the bottom surface of a microcard positioned adjacent to the upper surface of the sample block, the vacuum creating a force to urge the microcard against the upper surface of the sample block; and
- thermally cycling the microcard through a sequence of times and temperatures comprising at least a first temperature maintained for a first period of time and a second temperature maintained for a second period of time, with said second temperature being higher than said first temperature.
21. The method of claim 20, further comprising providing a gasket on an outer peripheral surface of the sample block, the gasket contacting and forming a substantial seal with the bottom surface of the microcard during thermal cycling of the microcard.
22. The method of claim 21, further comprising, prior to imparting a vacuum, pressing downward on the microcard to press the microcard against the gasket.
23. The method of claim 22, wherein the step of pressing downward on the microcard is performed by a microcard carrier in contact with the microcard.
24. The method of claim 20, further comprising, simultaneously with the step of thermally cycling the microcard, detecting the optical characteristics of the at least one sample of biological material.
25. The method of claim 20, wherein the step of thermally cycling the microcard includes controlling the temperature of the sample block by a temperature control system operatively connected to the sample block, the temperature being raised and lowered according to a user-defined profile.
26. The method of claim 20, wherein the step of thermally cycling the microcard further comprises at least two repetitions of said sequence of times and temperatures.
27. The method of claim 20, further comprising optically detecting the characteristics of the at least one sample of biological material.
28. A thermal cycling apparatus, comprising:
- a base, with said base defining a void therein;
- a vacuum port disposed for fluid communication with said void;
- support features disposed adjacent said void on the base, with said support features including uppermost surface regions defining a common plane; and
- a temperature control system configured for cycling at least one of the base and the support features through a sequence of times and temperatures comprising at least a first temperature maintained for a first period of time and a second temperature maintained for a second period of time, with said second temperature being higher than said first temperature and said cycling comprising at least two repetitions of said sequence of times and temperatures.
29. The thermal cycling device of claim 28, further comprising an optical detection system configured for detecting characteristics of samples of biological material contained in the microcard.
Type: Application
Filed: Jul 18, 2012
Publication Date: Feb 21, 2013
Applicant: LIFE TECHNOLOGIES CORPORATION (Carlsbad, CA)
Inventor: Adrian Fawcett (Carlsbad, CA)
Application Number: 13/552,529
International Classification: C40B 60/12 (20060101); C40B 30/04 (20060101);