Thermal cycler for automatic performance of the polymerase chain reaction with close temperature control

• US 6,703,236 B2
• Filed: 01/11/2000
• Issued: 03/09/2004
• Est. Priority Date: 11/29/1990
• Status: Expired due to Fees

• Current Assignee: Applied Biosystems LLC (Thermo Fisher Scientific Incorporated)
• Original Assignee: Applera Corporation (Thermo Fisher Scientific Incorporated)
• Inventors: Atwood, John Girdner
• Primary Examiner(s): Beisner, William H.
• Application Number:
  US09/481,552
• Publication Number:
  US 20020072112A1
• Time in Patent Office: 1,519 Days
• Field of Search: 435/286.1, 435/287.2, 435/288.4, 435/303.1, 435/305.3, 435/305.4, 435/809, 422/68.1, 422/102, 422/104, 422/63, 422/65
• US Class Current: 435/286.1
• CPC Class Codes: B01L 2200/147 Employing temperature sensors
• CPC Class Codes: B01L 2300/042 Caps; Plugs
• CPC Class Codes: B01L 2300/046 Function or devices integrated in the closure
• CPC Class Codes: B01L 2300/0829 Multi-well plates; Microtitration plates
• CPC Class Codes: B01L 2300/1822 using Peltier elements
• CPC Class Codes: B01L 2300/1827 using resistive heater
• CPC Class Codes: B01L 2300/185 using a liquid as fluid
• CPC Class Codes: B01L 3/50851 specially adapted for heating or cooling samples laboratory heating apparatus B01L7/00; incubators C12M
• CPC Class Codes: B01L 3/50853 with covers or lids
• CPC Class Codes: B01L 7/00 Heating or cooling apparatus autoclaves B01J3/04; Heat insulating devices
• CPC Class Codes: B01L 7/52 with provision for submitting samples to a predetermined sequence of different temperatures, e.g. for treating nucleic acid samples amplification or hybridisation processes per se C12Q1/68; controlling sequential reactions for synthesis B01J19/0046
• CPC Class Codes: G05D 23/1917 using digital means
• CPC Class Codes: Y10S 435/809 Incubators or racks or holders for culture plates or containers

Abstract

An instrument for performing highly accurate PCR employing a sample block in microtiter tray format. The sample block has local balance and local symmetry. A three zone film heater controlled by a computer and ramp cooling solenoid valves also controlled by the computer for gating coolant flow through the block controls the block temperature. Constant bias cooling is used for small changes. Sample temperature is calculated instead of measured. A platen deforms plastic caps to apply a minimum acceptable threshold force for seating the tubes and thermally isolates them. A cover isolates the block. The control software includes diagnostics. An install program tests and characterizes the instrument. A new user interface is used. Disposable, multipiece plastic microtiter trays to give individual freedom to sample tubes are taught.

Claims

1. In a combination of thermal cycler capable of performing a polymerase chain reaction comprising a temperature controlled metal block having an array of tapered wells in its top surface, said metal block being capable of receiving a plurality of individual reaction tubes having similarly tapered lower sections and upper sections which project above the top surface of the block when the tubes are placed in said wells, the improvement comprising means for seating said tubes in said wells, said seating means comprising:

resiliently deformable sealing caps removably attached to said tubes,

a platen,

support means for supporting the platen above the block,

displacement means associated with the support means for raising the platen above said caps and for lowering it so as to apply a force of at least 30 grams to each cap, and

controllable heating means to maintain said platen at a preselected temperature in the range of 94°

C. to 110°

C.

2. The combination of claim 1 wherein the preselected temperature is in the range of 100°

C. to 110°

C.

3. The combination of claim 1 wherein the preselected temperature is 105°

C.

4. In a combination of thermal cycler capable of performing a polymerase chain reaction comprising a temperature controlled metal block having an array of tapered wells in its top surface, said metal block being capable of receiving a plurality of individual reaction tubes having similarly tapered lower sections and upper sections which project above the top surface of the block when the tubes are placed in said wells, the improvement comprising means for seating said tubes in said wells, said seating means comprising:

sealing caps removably attached to said tubes,

a platen,

support means for supporting the platen above the block,

displacement means associated with the support means for raising the platen above said caps and for lowering it so as to apply a force of at least 30 grams to each cap, and

controllable heating means to maintain said platen at a preselected temperature in the range of 94°

C. to 110°

C.

5. The combination of claim 4 wherein the preselected temperature is in the range of 100°

C. to 110°

C.

6. The combination of claim 4 wherein the preselected temperature is 105°

C.

7. An apparatus capable of controlled automated performance of a polymerase chain reaction, said apparatus being capable of receiving at least one sample container containing a volume of a liquid sample mixture, which apparatus comprises:

a. a sample block having at least one well for said at least one sample container,

b. a computing apparatus,

c. a heating and cooling control controlled by said computing apparatus for changing the temperature of said sample block, and

d. temperature measurement apparatus for determining the temperature of said block;

wherein said computing apparatus includes a computer program for computing temperature of said liquid sample mixture as a function of temperature of said sample block, and said temperature of said liquid sample mixture which is computed is used to control said heating and cooling control; and

wherein said apparatus for controlled automated performance of polymerase chain reactions includes an enclosure for said sample block defining an enclosed ambient atmosphere, and wherein said sample block is comprised of a central region containing in an upper surface an array of sample wells for holding said at least one sample container, an end edge region comprising two end edges at opposite ends of said block which are in thermal contact with said enclosed ambient atmosphere, and a manifold region comprising two manifold edges at opposite sides of said block, wherein each said manifold edge is thermally coupled to a manifold.

8. The apparatus of claim 7 wherein said heating and cooling control comprises a heater having a central heating zone thermally coupled to said central region, an end edge heating zone thermally coupled to said edge region, and a manifold heating zone thermally coupled to said manifold region.

9. The apparatus of claim 8, wherein said computing apparatus comprises means for determining an actual heating power to be applied to each said heating zone in a first sample interval, including:

a. means for determining a theoretical second power representing total power to apply to said block in said sample interval without accounting for power losses,

b. means for determining theoretical third powers to be applied to each said zone in said first sample interval as a function of said theoretical second power,

c. means for determining power losses by said regions in said first sample interval, and

d. means for determining actual heating power to be applied to each said heating zone as a function of said theoretical third powers and said power losses by said regions.

10. The apparatus of claim 9 wherein said means for determining said theoretical second power includes:

a. means for determining a first fraction of a difference between the target sample temperature after ramping and the sample temperature in a second sample interval to be made up in said first sample interval, and

b. means for determining said theoretical second power as a function of said first fraction, said sample temperature in said second sample interval and said block temperature in said second sample interval.