Thermal cycler including a temperature gradient block

Abstract

A method in which a temperature gradient is generated across a “gradient” block, and an apparatus comprising a block across which a temperature gradient can be generated. By setting up such a gradient, multiple reaction mixtures held in wells on the gradient block can be simultaneously run at temperatures which differ only slightly, thereby permitting an optimum temperature for the reaction to be quickly identified. In a preferred embodiment the gradient block is integrated into a thermal cycler used for nucleic acid amplification reactions.

What is claimed is:  
     
         1 . A method for simultaneously reacting a plurality of reaction mixtures in an apparatus including a temperature gradient block comprising the steps of: 
 placing reaction mixtures in a plurality of reaction wells in said gradient block, said gradient block having a top portion, first and second oppposing portions, and a bottom portion, said plurality of reaction mixture wells being formed in said block between said opposing portions, and    generating a temperature gradient across said gradient block and between said opposing portions.    
     
     
         2 . A method according to  claim 1  Wherein said step of generating a temperature gradient comprises the steps of heating said first opposing portion of said gradient block, and cooling said second opposing portion of said gradient block.  
     
     
         3 . A method according to  claim 1  including the further step of controlling said temperature gradient using controlling means.  
     
     
         4 . A method according to  claim 3 ,wherein said controlling step comprises the steps of collecting and storing temperature set point and actual temperature data from said wells, and transmitting said information to a microprocessor.  
     
     
         5 . A method according to  claim 1  wherein said apparatus further comprises at least one additional heat conducting block having a top portion, first and second opposing portions, and a bottom portion, and a plurality of reaction mixture wells formed in said additional block between said opposing portions, the method further comprising the step of moving said reaction mixtures between said gradient block and said additional block or blocks.  
     
     
         6 . A method for automated temperature cycling of a reaction mixture using a thermal cycling apparatus comprising at least one heat conducting block, said block having a plurality of sample wells spaced between first and second opposing portions and in an upper surface thereof, the method comprising 
 placing reaction mixtures in said wells, and    generating a temperature gradient across said block and between said opposing portions by heating said first opposing portion and cooling said second opposing portion.    
     
     
         7 . An apparatus for generating a temperature gradient across a heat conducting block comprising: 
 a reaction mixture holder, said reaction mixture holder comprising a heat conducting block having a top portion, first and second opposing portions, and a bottom portion, a plurality of reaction mixture wells formed in said top portion, and between said first and second opposing portions,    a block heater positioned adjacent to said first opposing portion, and    a block cooler positioned adjacent to said second opposing portion.    
     
     
         8 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 7  wherein said apparatus further comprises controller means for controlling said block heater and block cooler.  
     
     
         9 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 7  wherein said heat conducting block comprises brass.  
     
     
         10 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 8  wherein said controller means comprises a microprocessor for collecting and storing temperature set point and actual temperature data.  
     
     
         11 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 7  wherein said plurality of wells in said heat conducting block are spaced across said top portion.  
     
     
         12 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 11  wherein said plurality of wells in said heat conducting block are spaced across said top portion in parallel, aligned rows.  
     
     
         13 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 7  wherein said holder further comprises a heater positioned adjacent to said bottom portion.  
     
     
         14 . An apparatus for generating a temperature gradient across a heat conducting block comprising holding means for holding a reaction mixture, said holding means comprising: 
 (i) a heat conducting block having a top portion, first and second opposing portions, and a bottom portion, and a plurality of reaction mixture wells formed in said top portion and between said first and second opposing portions; and    (ii) means for generating a temperature gradient across said heat conducting block and between said first and second opposing portions.    
     
     
         15 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 14  wherein said means for generating a temperature gradient comprises means for heating said first opposing portion of said block, and means for cooling said second opposing portion of said block.  
     
     
         16 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 14  wherein said apparatus further comprises at least one additional holding means for holding a reaction mixture, said additional holding means comprising: 
 (i) at least one additional heat conducting block including a plurality of reaction mixture wells; and  
 (ii) means for heating said additional heat conducting block.  
 
     
     
         17 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 14  wherein said heat conducting block comprises brass.  
     
     
         18 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 14  wherein said plurality of wells in said heat conducting block are spaced across said block in parallel, aligned rows.  
     
     
         19 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 14  wherein said apparatus further comprises controller means for generating said temperature gradient.  
     
     
         20 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 19  wherein said controller means comprises a microprocessor for collecting and storing temperature is set point and actual temperature data.  
     
     
         21 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 14  wherein said holder means further comprises a heating means for heating said bottom portion.  
     
     
         22 . An apparatus for generating a temperature gradient across a heat conducting block according to  claim 16  wherein said apparatus further comprises robot arm means, controlled by robot arm control means, for moving said reaction mixture between said holding means.  
     
     
         23 . An automated apparatus for performing molecular biological reactions comprising at least one temperature controlled block, said block having a plurality of reaction mixture wells spaced between first and second opposing portions and in an upper portion thereof, and a block heater positioned adjacent to said first opposing portion and capable of generating a temperature gradient between said first and second opposing portions.