EP1127619A2 - Verbesserungen von Thermozyklier-Geräten für PCR - Google Patents

Verbesserungen von Thermozyklier-Geräten für PCR Download PDF

Info

Publication number
EP1127619A2
EP1127619A2 EP01112394A EP01112394A EP1127619A2 EP 1127619 A2 EP1127619 A2 EP 1127619A2 EP 01112394 A EP01112394 A EP 01112394A EP 01112394 A EP01112394 A EP 01112394A EP 1127619 A2 EP1127619 A2 EP 1127619A2
Authority
EP
European Patent Office
Prior art keywords
sample
assembly
temperature
sample block
block
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP01112394A
Other languages
English (en)
French (fr)
Other versions
EP1127619B1 (de
EP1127619A3 (de
Inventor
John G. Atwood
Adrian Fawcett
Keith S. Ferrara
Paul M. Hetherington
Richard W. Noreiks
Douglas E. Olsen
John R. Widomski
Charles M. Wittmer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Applied Biosystems LLC
Applied Biosystems Inc
Original Assignee
PE Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to EP03022672A priority Critical patent/EP1386666B1/de
Priority to EP14198058.1A priority patent/EP2913109A1/de
Priority to EP09006229A priority patent/EP2090366B1/de
Priority to EP09013036.0A priority patent/EP2156892B1/de
Priority to EP09016131.6A priority patent/EP2186568B1/de
Application filed by PE Corp filed Critical PE Corp
Priority claimed from EP98913265A external-priority patent/EP0963250B1/de
Publication of EP1127619A2 publication Critical patent/EP1127619A2/de
Publication of EP1127619A3 publication Critical patent/EP1127619A3/de
Application granted granted Critical
Publication of EP1127619B1 publication Critical patent/EP1127619B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
    • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
    • B01L3/50—Containers for the purpose of retaining a material to be analysed, e.g. test tubes
    • B01L3/508—Containers for the purpose of retaining a material to be analysed, e.g. test tubes rigid containers not provided for above
    • B01L3/5085—Containers for the purpose of retaining a material to be analysed, e.g. test tubes rigid containers not provided for above for multiple samples, e.g. microtitration plates
    • B01L3/50853—Containers for the purpose of retaining a material to be analysed, e.g. test tubes rigid containers not provided for above for multiple samples, e.g. microtitration plates with covers or lids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
    • B01L7/00—Heating or cooling apparatus; Heat insulating devices
    • B01L7/52—Heating or cooling apparatus; Heat insulating devices with provision for submitting samples to a predetermined sequence of different temperatures, e.g. for treating nucleic acid samples
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
    • B01L2300/00—Additional constructional details
    • B01L2300/08—Geometry, shape and general structure
    • B01L2300/0809—Geometry, shape and general structure rectangular shaped
    • B01L2300/0829—Multi-well plates; Microtitration plates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
    • B01L2300/00—Additional constructional details
    • B01L2300/18—Means for temperature control
    • B01L2300/1805—Conductive heating, heat from thermostatted solids is conducted to receptacles, e.g. heating plates, blocks
    • B01L2300/1822—Conductive heating, heat from thermostatted solids is conducted to receptacles, e.g. heating plates, blocks using Peltier elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
    • B01L2300/00—Additional constructional details
    • B01L2300/18—Means for temperature control
    • B01L2300/1805—Conductive heating, heat from thermostatted solids is conducted to receptacles, e.g. heating plates, blocks
    • B01L2300/1827—Conductive heating, heat from thermostatted solids is conducted to receptacles, e.g. heating plates, blocks using resistive heater

Definitions

  • This invention pertains to the field of computer controlled instruments for performing the Polymerase Chain Reaction (PCR). More particularly, the invention pertains to automated instruments that perform the reaction simultaneously on many samples and produce very precise results by using thermal cycling.
  • PCR Polymerase Chain Reaction
  • the reaction mixture is comprised of various components including the DNA to be amplified and at least two primers sufficiently complementary to the sample DNA to be able to create extension products of the DNA being amplified.
  • a key to PCR is the concept of thermal cycling: alternating steps of melting DNA, annealing short primers to the resulting single strands, and extending those primers to make new copies of double-stranded DNA. In thermal cycling the PCR reaction mixture is repeatedly cycled from high temperatures of around 90°C for melting the DNA, to lower temperatures of approximately 40°C to 70°C for primer annealing and extension.
  • the chemical reaction has an optimum temperature for each of its stages. Thus, less time spent at non optimum temperature means a better chemical result is achieved. Also a minimum time for holding the reaction mixture at each incubation temperature is required after each said incubation temperature is reached. These minimum incubation times establish the minimum time it takes to complete a cycle. Any time in transition between sample incubation temperatures is time added to this minimum cycle time. Since the number of cycles is fairly large, this additional time unnecessarily heightens the total time needed to complete the amplification.
  • sample tubes are inserted into sample wells on a metal block.
  • the temperature of the metal block is cycled according to prescribed temperatures and times specified by the user in a PCR protocol file.
  • the cycling is controlled by a computer and associated electronics.
  • the samples in the various tubes experience similar changes in temperature.
  • differences in sample temperature are generated by non-uniformity of temperature from place to place within the sample metal block. Temperature gradients exist within the material of the block, causing some samples to have different temperatures than others at particular times in the cycle. Further, there are delays in transferring heat from the sample block to the sample, and those delays differ across the sample block.
  • an apparatus for performing the Polymerase Chain Reaction comprising an assembly capable of cycling samples through a series of temperature excursions, a heated cover and a computer to control the process.
  • the invention further encompasses a sample block with low thermal mass for rapid temperature excursions.
  • the sample block is preferably manufactured from silver for uniform overall heat distribution and has a bottom plate for uniform lateral heat distribution.
  • a center pin is used as a conducting path to a heat sink.
  • the invention also provides a method and apparatus for achieving rapid heating and cooling using Peltier thermoelectric devices. These devices are precisely matched to each other. They are constructed using die cut alumina on one side to minimize thermal expansion and contraction. The devices are constructed of bismuth telluride using specific dimensions to achieve matched heating and cooling rates. They are designed using minimal copper thicknesses and minimal ceramic thicknesses to further reduce their heat load characteristics and are assembled using a specific high temperature solder in specified quantities.
  • the invention is also directed to a heatsink constructed with a perimeter trench to limit heat conduction and losses from its edges. Furthermore, the heatsink has an associated variable speed fan to assist in both maintaining a constant temperature and in cooling.
  • the invention is also directed to a clamping mechanism to hold the sample block to the heat sink with the thermoelectric devices positioned in between.
  • the mechanism is designed to provide evenly distributed pressure with a minimal heat load.
  • the design allows the use of thermal grease as an interface between the sample block, and the thermoelectric devices and between the thermoelectric devices and the heatsink.
  • the perimeter heater is positioned around the sample block to counter the heat loss from the edges. Power is applied to the heater in proportion to the sample block temperature with more power applied when the sample block is at higher temperatures and less power applied when the sample block is at lower temperatures.
  • a heated cover designed to keep the sample tubes closed during cycling and to heat the upper portion of the tubes to prevent condensation.
  • the heated cover applies pressure on the sample tube cap perimeter to avoid distorting the cap's optical qualities.
  • the cover is self-aligning, using a skirt which mates with a sample tube tray.
  • the invention is also directed to a method and apparatus for determining an ideal temperature ramp rate which is determined so as to take advantage of sample block temperature overshoots and undershoots in order to minimize cycle time.
  • the invention also includes a method and apparatus for characterizing the thermal power output from the thermal electric cooling devices to achieve linear temperature control and linear and non-linear temperature ramps.
  • the invention is further directed to a method for predicting the actual temperature of the reaction mixture in the sample vials at any given time during the PCR protocol.
  • the invention also includes a method and apparatus for utilizing calibration diagnostics which compensate for variations in the performance of the thermoelectric devices so that all instruments perform identically.
  • the thermal characteristics and performance of the assembly comprised of the sample block, thermal electric devices and heatsink, is stored in an on-board memory device, allowing the assembly to be moved to another instrument and behave the same way.
  • PCR it is desirable to change the sample temperature between the required temperatures in the cycle as quickly as possible for several reasons.
  • the chemical reaction has an optimum temperature for each of it's stages and as such less time spent at non-optimum temperatures means a better chemical result is achieved.
  • a minimum time is usually required at any given set point which sets a minimum cycle time for each protocol and any time spent in transition between set points adds to this minimum time. Since the number of cycles is usually quite large, this transition time can significantly add to the total time needed to complete the amplification.
  • the absolute temperature that each reaction tube attains during each step of the protocol is critical to the yield of product. As the products are frequently subjected to quantitation, the product yield from tube to tube must be as uniform as possible and therefore both the steady-state and dynamic thermal uniformity must be excellent across the block.
  • Peltier thermoelectric devices These are constructed of pellets of n-type and p-type bismuth telluride connected alternately in series. The interconnections between the pellets is made with copper which is bonded to a substrate, usually a ceramic (typically alumina).
  • the block geometry must also meet the necessary thermal uniformity requirements because it is the primary contributor to lateral conduction and therefore evens out any variation in thermal uniformity of the thermoelectric coolers themselves.
  • the conflicting requirements of rapid ramp rates (indicating low thermal mass) and high lateral conduction (indicating a large material mass) are met by concentrating the bulk of the block structure in a base plate, and minimizing the thermal mass of the upper portion of the block which holds the sample tubes.
  • the optimal material for block fabrication is pure silver which has relatively low thermal mass and very good thermal conduction. Silver also lends itself well to electroforming. In practice the optimal block geometry has a light electroformed upper portion to hold the sample tubes fixed to a relatively thick base plate which provides lateral conduction.
  • the thermal mass of the block is concentrated in the base plate where the material contributes the most to thermal uniformity.
  • the electroformed portion of the block has a minimum thickness which is defined by two parameters: first, the material cannot be so thin as to make it too delicate for normal handling; second, the wall thickness is required to conduct heat out of the upper regions of the sample tube. Circulation in the sample itself is achieved by convection inside the tube and sample temperature is relatively uniform along the height of the tube, but good thermal conductivity between the tube walls and the base plate increases the effective surface area available for conduction of heat between the sample and the base plate.
  • the base plate thickness has a minimum value defined by lateral conduction requirements which is a function of the thermal uniformity of the thermoelectric coolers and structural rigidity.
  • thermoelectric cooler Another contributor to the thermal mass is the alumina ceramic layers which form part of the structure of the thermoelectric cooler itself.
  • alumina ceramic layers which form part of the structure of the thermoelectric cooler itself.
  • the thickness of the layers should be minimized as much as possible, in this case the practical limit of thinness for the alumina thickness is defined by the manufacturing requirements of thermoelectric cooler fabrication.
  • This particular layer of ceramic could in principal be replaced by a different layer altogether such as a thin sheet of Kapton which would reduce the thermal mass even more, but at the present time although coolers are available with this structure, reliability is unproven. It is anticipated that once the technology has been developed further, then a cooler of such a design may be preferred. However, the thin alumina layers also contribute to system reliability.
  • the copper conductors within the cooler are a significant thermal load and are not overlooked in the design of the system.
  • the thickness of the copper traces is defined by the requirement of carrying current through the device. Once the current is known the required copper thickness can be calculated.
  • Figure 1 shows a cross sectional view of a portion of the sample block 36 which typically has 96 wells 20 , each for receiving a sample vial.
  • the sample block is constructed of silver and comprises an upper support plate 21 and the sample wells 20 electroformed as one piece fastened to a base plate 22 .
  • the base plate 22 provides lateral conduction to compensate for any difference in the thermal power output across the surface of each individual thermal electric device and for differences from one thermal electric device to another.
  • the amount of conduction required is quite small and a 1.5mm diameter stainless steel pin has been found to be sufficient.
  • a pin made of the polymer ULTEM, manufactured by General Electric may also be used. As more fully described below, the pin also serves to help position and lock into place components of the assembly illustrated in Figure 4.
  • Thermal uniformity of the sample block is critical to PCR performance.
  • One of the most significant factors affecting the uniformity is variations in the thermal electric device performance between devices. The most difficult point at which to achieve good uniformity is during a constant temperature cycle far from ambient. In practice this is a constant temperature cycle at approximately 95°C.
  • the thermal electric devices are matched under these conditions to make a set of devices for each heatsink assembly which individually produce the same temperature for a given input current.
  • the thermal electric devices are matched to within 0.2°C in any given set, this value being derived from the maximum discrepancy that can be rectified by the lateral conduction of the sample block baseplate.
  • FIG. 2A shows a side view of a typical Peltier thermal electric device 60 .
  • the device is composed of bismuth telluride pellets 30, sandwiched between two alumna layers 26 .
  • the pellets are electrically connected by solder joints 28 to copper traces 29 plated onto the alumina layers.
  • One alumina layer has an extension 31 to facilitate electrical connections. The thickness of the extended areas is reduced to decrease the thermal load of the device.
  • Figure 2 shows an isometric view of a typical Peltier thermal electric device.
  • the alumina layer 26 that forms the outer wall of the thermal electric device, expands and contracts during temperature cycling at a different rate than the sample block 19 .
  • the motion of the alumina is transmitted directly to the solder 28 connecting the internal bismuth telluride pellets 30 .
  • This motion can be reduced dramatically by cutting the alumina into small pieces 32 called die so that the field of expansion is small.
  • the minimum size of the die is defined by the size of the copper traces required to carry current through the thermal electric device and the requuirements thta the device retain some strength for handling.
  • the reaction temperatures are above ambient and in the range 35 to 96°C.
  • the block is heated or cooled between two above ambient temperatures where the flow of heat due to conduction is from the block to the heat sink.
  • the key to optimizing the system cycle time, given an optimized block configuration, is to balance the boost to the ramp rate when cooling provided by the conduction, against the boost provided to the heating ramp rate by the Joule effect of resistance heating.
  • the heating ramp rate would be increased by increasing the height of the pellet. This is because the conduction path through the thermal electric device would be made longer thereby decreasing k . This also has the effect of reducing the current required to maintain a given block temperature in the steady state. During the down ramp, i.e. cooling the block, the decreased k means that the conduction contribution will be reduced and so the down ramp rate will be reduced.
  • the optimized thermal electric device can be derived by adjusting the height of the Bismuth Telluride pellets until the heating rate matches the cooling rate.
  • the resistance must be measured as an AC resistance because of the Seebeck effect. Because the geometry defines the resistance of the device, another design boundary is encountered in that the device must use a cost effective current to voltage ratio because too high a current requirement pushes up the cost of the amplifier.
  • the balanced solution for the silver electroformed block described above is :
  • the current source in the present embodiment consists of a class D type switch-mode power amplifier with a current sending resistor in series with the device and ground.
  • High temperature solder has been shown to not only have improved high temperature performance but it is also generally more resistant to failure by stress reversals and hence is most appropriate in this application.
  • the solder used in this invention may be of the type as described in U.S. Patent 5,441,576.
  • Figure 3 shows the heatsink 34 assembled with the thermal electric devices 39 and the sample block 36 .
  • a locating frame 41 is positioned around the thermal electric devices to align them with the sample block and the heatsink to ensure temperature uniformity across the sample block.
  • the frame is composed of Ultem or other suitable material and has tabs 43 at its corners to facilitate handling.
  • the heatsink 34 has a generally planer base 34 and fins 37 extending from base 35 .
  • the thermal mass of the heat sink is considerably larger than the thermal mass of the sample block and samples combined.
  • the sample block and samples together have a thermal mass of approximately 100 joules/°K and that of the heat sink is approximately 900 joules/°K. This means that the sample block clearly changes temperature much faster than the heat sink for a given amount of heat pumped.
  • the heat sink temperature is controlled with a variable speed fan as shown in Figure 9).
  • the temperature of the heat sink is measured by a thermistor 38 placed in a recess 40 within the heatsink and the fan speed is varied to hold the heat-sink at approximately 45°C which is well within the normal PCR cycling temperature range, where maintaining a stable heat sink temperature improves the repeatability of system performance.
  • the block temperature is set to a value below ambient then the heat sink is set to the coolest achievable temperature to reduce system power consumption and optimize block thermal uniformity. This is accomplished simply operating the fan at full speed.
  • the heatsink temperature uniformity is reflected in the uniformity of the block temperature. Typically the heatsink is warmer in the middle than it is at the edges and this adds to other effects that lead to the corners of the block being the coldest.
  • a trench 44 is cut into the heat sink outside the perimeter of the thermal electric device area to limit the conduction of heat and decreases edge losses from the area bounded by the trench.
  • Thermal electric device manufacturers recommend that thermal electric devices be held under pressure to improve life-expectancy. (The pressure recommended is often defined by the thermal interface media selected.) The pressure that is recommended varies from manufacturer to manufacturer but is in the range of 30 to 100 psi for cycling applications.
  • the silver block is relatively flexible and soft it cannot transmit lateral clamping pressure very effectively.
  • the thermal interface media is thermal grease, the clamping force required is low.
  • FIG 4 shows an exploded view of the assembly with the preferred embodiment of the clamping mechanism.
  • Each clamp 46 is made up of a series of fingers 48 extending from a spine 49 .
  • the fingers 48 are sized, shaped and spaced so as to fit between the wells 20 of the sample block 36 and thus apply pressure at a corresponding series of points on the base plate 22 of the sample block 36.
  • the open honeycomb structure of the electroformed sample wells allows the fingers to be inserted some distance into the block, thereby applying the pressure more evenly than an edge clamping scheme would.
  • These fingers apply pressure at a series of local points to minimize the contact area between the mass of the clamp and the sample block so that the clamp does not add significantly to the thermal load.
  • the clamps are molded from a glass filled plastic which has the necessary rigidity for this application.
  • the resulting even pressure distribution ensures that the full area of the thermal electric devices is in good thermal contact with the block and the heatsink reducing local thermal stresses on the thermal electric devices.
  • FIG 4 shows other important features of the invention.
  • a printed circuit board 82 a memory device 96 for storing data and surrounds the thermal electric devices and provides electrical connections.
  • Alignment pins 84 are seated in holes 86 in the heatsink and protrudes through alignment holes 88 to align the printed circuit board with the heatsink.
  • the locating frame 41 is positioned around the thermal electric devices and has a cross beam 90 with a through hold 92.
  • Pin 24 (shown in Figure 1) fits into a hole (not shown) in the sample block, extends through hold 92 in the locating frame and further extends into hole 94 in the heatsink.
  • a perimeter heater is positioned around the sample block to eliminate heat losses from its edges.
  • the heater is a film type, having low mass with inside dimensions slightly larger than the sample block.
  • Figure 10 shows the perimeter heater 74 and its approximate location surrounding the sample:block 36. The heater is not fastened in place, it is simply positioned in the air around the perimeter of the sample block in order to warm the air in the immediate vicinity.
  • Figure 11 shows a detailed view of the perimeter heater 74 .
  • the heater is rectangular as determined by the dimensions of the sample block and is manufactured so that it has separate power densities in specific areas to reflect the varying amounts of heat loss around the perimeter of the block.
  • Matching lower power density regions 76 (0.73 W/in 2 ) are located in the center portions of the short sides of the rectangle and matching higher power density regions 78 (1.3 W/in 2 ) are located in the longer sides, extending into the shorter sides.
  • the power applied to the perimeter heater is regulated to correspond to the temperature of the sample block, with more power applied to the heater at higher block temperatures and less applied at lower block temperatures.
  • Figure 5 shows the heated cover 57 .
  • the heated cover applies pressure to the sample vial caps to ensure that they remain tightly closed when the sample is heated.
  • the cover is heated under computer control to a temperature above that of the sample to ensure that the liquid does not condense onto the tube cap and instead remains in the bottom of the tube where thermal cycling occurs.
  • the heated platen 54 in the present invention does not press on the dome of the cap but instead presses on the cap perimeter.
  • the platen has a surface shaped in this manner so that optical caps are not distorted by the application of pressure.
  • tubes that have been cycled can be directly transferred to an optical reader without the need to change the cap.
  • the heated platen has recesses 56 in it to clear the cap domes, there is a need to align the plate to the tube positions before applying pressure to avoid damage to the tubes. This is accomplished by use of a "skirt" 58 around the perimeter of the platen which aligns to the microtiter tray before the plate touches the tube caps.
  • the cover has a sliding mechanism similar to that used on the PYRIS Differential Scanning Calorimeter by the Perkin Elmer Corporation allowing the cover to slide back to allow sample vials to be inserted into the sample block and forward to cover the sample block and move down engage the vials.
  • the optimized ramp rate has been empirically determined to be 4°C/sec. Any system which has a higher block ramp rate than this cannot fully utilize the benefits temperature of overshoots and consequently achieves an insignificant reduction in cycle time.
  • Figure 6 is a chart depicting the Up Ramp (heating rate) vs. Power and Figure 7 is a chart depicting the Down Ramp (cooling rate) vs. Power.
  • the Joule heating and the Seebeck heat pumping both act to heat the sample block against conduction.
  • the Seebeck heat pumping and conduction act against the Joule heating.
  • significant power is required to hold the block temperature steady against the flow of heat out of the block by conduction. Therefore even with zero power applied, the block will cool at a significant rate.
  • the Seebeck effect increases the cooling obtained.
  • the joule effect which is proportional to the square of the current, quickly starts to take over acting against the Seebeck cooling. Therefore a point is reached where applying additional power acts against the required effect of cooling. In the heating mode these two effects act together against conduction and no ceiling is reached.
  • the heating power vs. input current is approximately linear. This is why the design criteria centers around meeting the cooling rate requirements; the heating rate can always be achieved by the application of more power.
  • Equation 1 The solution to equation 1 is used to determine the current value, I , which will result in the desired Q under the current temperature conditions. This process is repeated periodically during temperature transitions.
  • the sample has a time constant with respect to the block temperature that is a function of the sample tube and tube geometry which, because the tube is an industry standard, cannot be reduced. This means that even if the sample tube wall temperature is changed as a step function e.g. by immersion in a water bath, the sample will have a finite ramp time as the sample temperature exponentially approaches the set point. This can be compensated for by dynamically causing the block to overshoot the programmed temperature in a controlled manner.
  • Figure 8 is a chart for predicting and compensating for temperature overshoots and undershoots.
  • Tbn+1 Ts n + (Tb n+1 - Ts n )*0.174/RC
  • Tsf n (Tb n - Ts n - mRC)(1-e -trn/RC ) + mtr n + Ts n
  • Tb the measured block temperature
  • Ts is the calculated sample temperature
  • Tsf is the final calculated sample temperature if the block is ramped down at time t n
  • R is the thermal resistance between the sample block and the sample
  • C is the thermal capacitance of the sample
  • m is the slope of a line defined by the points Tb and Tsf and tr is the time for the sample block to return to the set point if the system caused it to ramp
  • the system causes the sample block to ramp back to the set point at the same rate it was ramping away. If the resulting Tsf n is outside the particular error window then the system causes the sample block to continue to ramp away from the set point at the same rate. While ramping back toward the set point the same proportional integral derivative (PID) control loop described above is applied.
  • PID proportional integral derivative
  • the temperature of a sample in a sample vial is determined by using the model illustrated in Figure 13 where:
  • the coefficients are recalculated at the beginning of each PCR protocol to account for the currently selected sample volume.
  • TSmp and TPlastic are recalculated for every iteration of the control task.
  • Tblk (Tsmp - coef1*TCvr0 - coef2*TPlastic0 - coef4*slope - coef5*TSmp0)/coef3
  • the control software includes calibration diagnostics which permit variation in the performance of thermoelectric coolers from instrument to instrument to be compensated for so that all instruments perform identically.
  • the sample block, thermal electric devices and heatsink are assembled together and clamped using the clamping mechanism described above.
  • the assembly is then ramped through a series of known temperature profiles during which its actual performance is compared to the specified performance. Adjustments are made to the power supplied to the thermal electric devices and the process is repeated until actual performance matches the specification.
  • the thermal characteristics obtained during this characterization process are then stored in a memory device residing on the assembly. This allows the block assembly to be moved from instrument to instrument and still perform within specifications.
  • the typical failure mode for the thermal electric devices is an increase in resistance caused by a fatigue failure in a solder joint. This results in an increase in the temperature of that joint which stresses the joint further, rapidly leading to catastrophic failure. It has been determined empirically that devices that exhibit an increase in AC resistance of approximately 5% after about 20,000 to 50,000 temperature cycles will shortly fail. The AC resistance of the thermal electric devices are monitored by the instrument to detect imminent failures before the device in question causes a thermal uniformity problem.
  • This embodiment automates the actual measurement using a feedback control system and eliminates the need to remove the thermal electric device from the unit.
  • the control system compensates for the temperature difference between the two surfaces of the thermal electric device caused by the heat sink attached to one side and the sample block attached to the other.
  • the control system causes the thermal electric device to equalize its two surface temperatures and then the AC resistance measurement is made.
  • the micro-controller performs a polynomial calculation at the referenced time of the AC measurement to compensate for ambient temperature error.
  • Figure 9 shows the sample block 36, a layer of thermal electric device 60 and heatsink 34 interfaced with the system microcontroller 62 and bipolar power amplifier 64.
  • the temperature sensor already present in the heatsink 38 and an additional temperature sensor attached to the sample block 36 with a clip (not shown) formed of music wire are utilized to determine the temperature differential of the surfaces of the thermal electric device.
  • the bipolar power amplifier supplies current in two directions to the device. Current in one direction heats the sample block and current in the other direction cools the sample block.
  • the bipolar power amplifier also has signal conditioning capability to measure the AC voltage and AC current supplied to the thermal electric device.
  • a band pass filter 68 is incorporated into the signal conditioning to separate an AC measurement signal from the steady state signal that produces a null condition for the temperature difference across the thermal electric device.
  • the micro-controller incorporates the necessary capability to process the measurement information and perform the feedback in real time. It also stores the time history of the AC resistance and the number of temperature cycles of the thermal electric device and displays the information to the operator on the display 70 .
  • the AC measurement is normally done during initial turn on. However, it can be activated when self diagnostics are invoked by the operator using the keypad 72 .
  • An analog to digital and digital to analog converter along with signal conditioning for the temperature sensors and AC resistance measurement is also integrated into the micro-controller in order for it to perform its digital signal processing.
  • the thermal electric devices are protected from moisture in the environment by seals and the chamber is kept dry with the use of a drying agent such as silica gel.
  • the seal connects from the silver electroform to the surrounding support and as such adds to the edge losses from the block. These losses are minimized by the use of a low thermal conductivity pressure seal 98 and by the use of the perimeter heater described above.
  • the seal 98 has a cross-section generally in the shape of a parallelogram with several tabs 100 spaced about the lower surface of seal 98 for holding seal 98 to the edge of the sample block as shown in Figure 15.
  • the seal 98 is installed by first applying RTV rubber (not shown) around the perimeter 110 of the upper portion of the sample block. The seal 98 is then placed on the RTV rubber. More RTV rubber is applied to the perimeter 120 of the seal and then a cover (not shown) is installed which contacts the RTV rubber - seal combination. The cover has a skirt which also contacts a gasket (not shown) on the printed circuit board to effect a more effective seal.

Landscapes

  • Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Clinical Laboratory Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biochemistry (AREA)
  • Molecular Biology (AREA)
  • Analytical Chemistry (AREA)
  • Hematology (AREA)
  • Apparatus Associated With Microorganisms And Enzymes (AREA)
  • Automatic Analysis And Handling Materials Therefor (AREA)
EP01112394A 1997-03-28 1998-03-30 Einrichtung für Thermozyklier-Geräten für PCR Expired - Lifetime EP1127619B1 (de)

Priority Applications (5)

Application Number Priority Date Filing Date Title
EP14198058.1A EP2913109A1 (de) 1997-03-28 1998-03-30 Anordnung für Thermocycler für PCR
EP09006229A EP2090366B1 (de) 1997-03-28 1998-03-30 Verbesserungen in einer thermischen Schaltung für PCR
EP09013036.0A EP2156892B1 (de) 1997-03-28 1998-03-30 PCR Thermalcycler
EP09016131.6A EP2186568B1 (de) 1997-03-28 1998-03-30 Baugruppe für Thermozykliergerät für PCT
EP03022672A EP1386666B1 (de) 1997-03-28 1998-03-30 Thermo-Zyklus-Vorrichtung zur Ausführung der Polymerase-Kettenreaktion

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
US4175497P 1997-03-28 1997-03-28
US41754P 1997-03-28
US4612297P 1997-05-09 1997-05-09
US46122P 1997-05-09
EP98913265A EP0963250B1 (de) 1997-03-28 1998-03-30 Thermo-zyklus-vorrichtung zur ausführung der polymerase-kettenreaktion

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
EP98913265A Division EP0963250B1 (de) 1997-03-28 1998-03-30 Thermo-zyklus-vorrichtung zur ausführung der polymerase-kettenreaktion

Related Child Applications (3)

Application Number Title Priority Date Filing Date
EP03022672A Division EP1386666B1 (de) 1997-03-28 1998-03-30 Thermo-Zyklus-Vorrichtung zur Ausführung der Polymerase-Kettenreaktion
EP14198058.1A Division EP2913109A1 (de) 1997-03-28 1998-03-30 Anordnung für Thermocycler für PCR
EP09016131.6A Division EP2186568B1 (de) 1997-03-28 1998-03-30 Baugruppe für Thermozykliergerät für PCT

Publications (3)

Publication Number Publication Date
EP1127619A2 true EP1127619A2 (de) 2001-08-29
EP1127619A3 EP1127619A3 (de) 2001-09-05
EP1127619B1 EP1127619B1 (de) 2003-10-08

Family

ID=27239812

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01112394A Expired - Lifetime EP1127619B1 (de) 1997-03-28 1998-03-30 Einrichtung für Thermozyklier-Geräten für PCR

Country Status (1)

Country Link
EP (1) EP1127619B1 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10228431A1 (de) * 2002-06-26 2004-01-22 Eppendorf Ag Laborprobentemperiervorrichtung mit Aufnahmen
WO2004035213A1 (en) * 2002-10-15 2004-04-29 The Regents Of The University Of California Thermal cycler with modular structure
EP2076605B2 (de) † 2006-06-23 2020-08-26 Applied Biosystems, LLC Kühlung in einem thermocycler mit heizrohren

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2198968B1 (de) * 2008-12-16 2018-10-17 F. Hoffmann-La Roche AG Systeme und Verfahren zum Überwachen einer thermoelektrischen Heiz- und Kühlvorrichtung

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4865986A (en) * 1988-10-06 1989-09-12 Coy Corporation Temperature control apparatus
EP0488769A2 (de) * 1990-11-29 1992-06-03 The Perkin-Elmer Corporation Thermisches Kreisprozessgerät zur automatischen Ausführung der Polymerase-Kettenreaktion bei feiner Temperaturregelung
EP0642831A1 (de) * 1993-09-10 1995-03-15 F. Hoffmann-La Roche Ag Vorrichtung zur automatischen Durchführung von Temperaturzyklen
US5410130A (en) * 1994-04-20 1995-04-25 Ericomp, Inc. Heating and temperature cycling

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4865986A (en) * 1988-10-06 1989-09-12 Coy Corporation Temperature control apparatus
EP0488769A2 (de) * 1990-11-29 1992-06-03 The Perkin-Elmer Corporation Thermisches Kreisprozessgerät zur automatischen Ausführung der Polymerase-Kettenreaktion bei feiner Temperaturregelung
EP0642831A1 (de) * 1993-09-10 1995-03-15 F. Hoffmann-La Roche Ag Vorrichtung zur automatischen Durchführung von Temperaturzyklen
US5410130A (en) * 1994-04-20 1995-04-25 Ericomp, Inc. Heating and temperature cycling

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10228431A1 (de) * 2002-06-26 2004-01-22 Eppendorf Ag Laborprobentemperiervorrichtung mit Aufnahmen
DE10228431B4 (de) * 2002-06-26 2004-08-26 Eppendorf Ag Laborprobentemperiervorrichtung mit Aufnahmen
WO2004035213A1 (en) * 2002-10-15 2004-04-29 The Regents Of The University Of California Thermal cycler with modular structure
EP2076605B2 (de) † 2006-06-23 2020-08-26 Applied Biosystems, LLC Kühlung in einem thermocycler mit heizrohren

Also Published As

Publication number Publication date
EP1127619B1 (de) 2003-10-08
EP1127619A3 (de) 2001-09-05

Similar Documents

Publication Publication Date Title
US7133726B1 (en) Thermal cycler for PCR
EP2090366B1 (de) Verbesserungen in einer thermischen Schaltung für PCR
WO1998043740A9 (en) Improvements in thermal cycler for pcr
US8859271B2 (en) Thermal cycling apparatus and method for providing thermal uniformity
EP2338599B1 (de) Laborgerät mit einer Anordnung zum Temperieren von Proben und Verfahren zum Temperieren von Proben
EP1127619B1 (de) Einrichtung für Thermozyklier-Geräten für PCR
EP1386666B1 (de) Thermo-Zyklus-Vorrichtung zur Ausführung der Polymerase-Kettenreaktion
US11474055B2 (en) High sample throughput differential scanning calorimeter
CA2464973A1 (en) Thermal cycler for pcr

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

17P Request for examination filed

Effective date: 20010521

AC Divisional application: reference to earlier application

Ref document number: 963250

Country of ref document: EP

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

RIN1 Information on inventor provided before grant (corrected)

Inventor name: WIDOMSKI, JOHN R.

Inventor name: ATWOOD, JOHN G.

Inventor name: OLSEN, DOUGLAS E.

Inventor name: HETHERINGTON, PAUL M.

Inventor name: FAWCETT, ADRIAN

Inventor name: WITTMER, CHARLES M.

Inventor name: FERRARA, KEITH S.

Inventor name: NOREIKS, RICHARD W.

AKX Designation fees paid

Free format text: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

RTI1 Title (correction)

Free format text: ASSEMBLY FOR THERMAL CYCLER FOR PCR

RTI1 Title (correction)

Free format text: ASSEMBLY FOR THERMAL CYCLER FOR PCR

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AC Divisional application: reference to earlier application

Ref document number: 0963250

Country of ref document: EP

Kind code of ref document: P

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20031008

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20031008

Ref country code: BE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20031008

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 69818869

Country of ref document: DE

Date of ref document: 20031113

Kind code of ref document: P

REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: RITSCHER & PARTNER AG PATENTANWAELTE

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: APPLERA CORPORATION

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040108

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040108

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040119

NLT2 Nl: modifications (of names), taken from the european patent patent bulletin

Owner name: APPLERA CORPORATION

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040330

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040330

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040331

ET Fr: translation filed
REG Reference to a national code

Ref country code: FR

Ref legal event code: TP

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20040709

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040308

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20070519

Year of fee payment: 10

REG Reference to a national code

Ref country code: CH

Ref legal event code: PCAR

Free format text: RITSCHER & PARTNER AG;RESIRAIN 1;8125 ZOLLIKERBERG (CH)

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

Free format text: REGISTERED BETWEEN 20090514 AND 20090520

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20080330

NLS Nl: assignments of ep-patents

Owner name: APPLIED BIOSYSTEMS, LLC

Effective date: 20090813

NLT1 Nl: modifications of names registered in virtue of documents presented to the patent office pursuant to art. 16 a, paragraph 1

Owner name: APPLIED BIOSYSTEMS, INC.

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

Free format text: REGISTERED BETWEEN 20100121 AND 20100127

REG Reference to a national code

Ref country code: CH

Ref legal event code: PUE

Owner name: PPLIED BIOSYSTEMS, LLC

Free format text: APPLERA CORPORATION#850 LINCOLN CENTRE DRIVE#FOSTER CITY, CA 94404 (US) -TRANSFER TO- APPLIED BIOSYSTEMS, LLC#5791 VAN ALLEN WAY#CARLSBAD, CA 92008 (US)

REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: RITSCHER & PARTNER AG

REG Reference to a national code

Ref country code: FR

Ref legal event code: CD

Ref country code: FR

Ref legal event code: TP

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20110329

Year of fee payment: 14

Ref country code: SE

Payment date: 20110329

Year of fee payment: 14

REG Reference to a national code

Ref country code: NL

Ref legal event code: V1

Effective date: 20121001

REG Reference to a national code

Ref country code: SE

Ref legal event code: EUG

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121001

REG Reference to a national code

Ref country code: CH

Ref legal event code: PFA

Owner name: APPLIED BIOSYSTEMS, LLC, US

Free format text: FORMER OWNER: APPLIED BIOSYSTEMS, LLC, US

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 19

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20170213

Year of fee payment: 20

Ref country code: CH

Payment date: 20170314

Year of fee payment: 20

Ref country code: DE

Payment date: 20170321

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20170329

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 69818869

Country of ref document: DE

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20180329

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20180329