System and method for heating, cooling and heat cycling on microfluidic device

• US 7,544,506 B2
• Filed: 06/07/2004
• Issued: 06/09/2009
• Est. Priority Date: 06/06/2003
• Status: Active Grant

• Current Assignee: Revvity Health Sciences Incorporated (Revvity, Inc.)
• Original Assignee: Micronics Inc. (Sony Group Corp.)
• Inventors: Lancaster, Christy A, Bardell, Ronald L, Hayenga, Jon Wallace, Tonn, Jeffrey F, Breidford, Wayne, Weigl, Bernhard H
• Primary Examiner(s): Griffin; Walter D
• Assistant Examiner(s): EDWARDS, LYDIA E
• Application Number:
  US10/862,826
• Publication Number:
  US 20050129582A1
• Time in Patent Office: 1,828 Days
• Field of Search: 422/100, 435/287.2, 435/288.5, 435/288.7, 435/309.1, 435/809
• US Class Current: 435/288.5
• CPC Class Codes: B01J 2219/00873 Heat exchange
• CPC Class Codes: B01L 2200/147 Employing temperature sensors
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2300/18 Means for temperature control
• CPC Class Codes: B01L 2300/1822 using Peltier elements
• CPC Class Codes: B01L 2300/185 using a liquid as fluid
• CPC Class Codes: B01L 2300/1877 using chemical reactions
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• 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: Y10S 435/809 Incubators or racks or holders for culture plates or containers

Abstract

An integrated heat exchange system on a microfluidic card. According to one aspect of the invention, the portable microfluidic card has a heating, cooling and heat cycling system on-board such that the card can be used portably. The microfluidic card includes one or more reservoirs containing exothermic or endothermic material. Once the chemical process of the reservoir material is activated, the reservoir provides heat or cooling to specific locations of the microfluidic card. Multiple reservoirs may be included on a single card to provide varying temperatures. The assay chemicals can be moved to the various reservoirs to create a thermal cycle useful in many biological reactions, for example, Polymerase Chain Reaction (PCR) or rtPCR. According to another aspect of the invention, the integrated heat exchanger is an adjacent microfluidic circuit containing fluid that is either independently heated or cooled, or is an exothermic or endothermic material, such that the fluid in the adjacent circuit imparts a change in temperature to the assay fluid in an independent circuit. According to yet another aspect of the invention, a thermal electric cooler (TEC) is used for thermocycling the amplification chamber of a disposable microfluidic card.

Claims

1. A thermocycling apparatus for driving one complete polymerase chain reaction temperature cycle in less than or about 15 seconds, comprising:

a) a plastic card body comprising;

i) a first plate with a first surface and a second surface,

ii) a first amplification chamber formed in said first surface,

iii) a microfluidic assay fluid circuit fluidly connected to said first amplification chamber, and

iv) a plastic heat exchange film covering and sealing over said first amplification chamber, said plastic heat exchange film with interior surface facing said first surface of said first plate and with oppositely facing exterior surface; and

b) a first heat transfer element in thermal contact with said exterior surface of said plastic heat exchange film over said first amplification chamber,

wherein said plastic heat exchange film is sealed to said first surface with a double-sided ACA adhesive layer.

2. A thermocycling apparatus for driving one complete polymerase chain reaction temperature cycle in less than or about 15 seconds, comprising:

a) a plastic card body comprising;

i) a first plate with a first surface and a second surface,

ii) a first amplification chamber formed in said first surface,

iii) a microfluidic assay fluid circuit fluidly connected to said first amplification chamber, and

iv) a plastic heat exchange film covering and sealing over said first amplification chamber, said plastic heat exchange film with interior surface facing said first surface of said first plate and with oppositely facing exterior surface; and

b) a first heat transfer element in thermal contact with said exterior surface of said plastic heat exchange film over said first amplification chamber,

wherein said first heat transfer element further comprises a thermal pad with thermal conductivity of greater than or about 1.5 W/m-°

K.

3. A thermocycling apparatus for driving one complete polymerase chain reaction temperature cycle in less than or about 15 seconds, comprising:

a) a plastic card body comprising;

i) a first plate with a first surface and a second surface,

ii) a first amplification chamber formed in said first surface,

iii) a microfluidic assay fluid circuit fluidly connected to said first amplification chamber, and

iv) a plastic heat exchange film covering and sealing over said first amplification chamber, said plastic heat exchange film with interior surface facing said first surface of said first plate and with oppositely facing exterior surface;

b) a first heat transfer element in thermal contact with said exterior surface of said plastic heat exchange film over said first amplification chamber, said first heat transfer element comprising a circulating temperature-controlled heat exchanger fluid in thermal contact with said exterior surface of said plastic heat exchange film;

c) a pump for hot heat exchanger fluid having a fluid temperature HotIN greater or equal to the denaturation temperature of a nucleic acid hybrid in solution;

d) a pump for cold heat exchanger fluid having a fluid temperature ColdIN is less than or equal to the annealing temperature of a nucleic acid hybrid in solution; and

e) a means for mixing said hot heat exchanger fluid and said cold heat exchanger fluid in said plastic card body to produce said temperature-controlled heat exchanger fluid, said means comprising a heat exchanger circuit comprising;

i) a first inlet for circulating said hot heat exchanger fluid and a second inlet for circulating said cold heat exchanger fluid,

ii) a mixing chamber fluidically connected to said first inlet and said second inlet, and

iii) a hot-control fluid valve interposed between said first inlet and said mixing chamber and a cold-control fluid valve interposed between said second inlet and said mixing chamber,

iv) a channel for circulating said temperature-controlled heat exchanger fluid across said external surface of said heat exchange film;

wherein said hot-control and cold-control fluid valves are microfluidic valves configured for admitting said hot heat exchanger fluid and said cold heat exchanger fluid to said mixing chamber in controlled amounts, thereby controlling the temperature of said temperature-controlled heat exchanger fluid and said amplification chamber, and

wherein said heat exchanger fluid is a fluorinated hydrocarbon fluid and said heat exchanger circuit further comprises a debubbler.

4. A thermocycling apparatus for driving one complete polymerase chain reaction temperature cycle in less than or about 15 seconds, comprising:

a) a plastic card body comprising;

i) a first plate with a first surface and a second surface,

ii) a first amplification chamber formed in said first surface,

iii) a microfluidic assay fluid circuit fluidly connected to said first amplification chamber, and

iv) a plastic heat exchange film covering and sealing over said first amplification chamber, said plastic heat exchange film with interior surface facing said first surface of said first plate and with oppositely facing exterior surface; and

b) a first heat transfer element in thermal contact with said exterior surface of said plastic heat exchange film over said first amplification chamber,

wherein said interior surface of said plastic heat exchange film is a polyethylene terephthalate film of thickness less than or equal to 0.004 inches, and

wherein said first heat transfer element is a thermal electric cooler in thermal contact with said exterior surface of said plastic heat exchange film of polyethylene terephthalate over said first amplification chamber.

5. A thermocycling apparatus of claim 4 wherein said first heat transfer element further comprises a thermal pad with thermal conductivity of greater than about 1.5 W/m-°

K interposed between said thermal electric cooler and said exterior surface of said plastic heat exchange film.