Abstract: A thermal cycling system and method are provided herein, The thermal cycling system for performing a biological reaction at two or more different temperatures comprises: a) a heat source for setting at a fixed temperature; b) a reaction vessel containing material upon which the biological reaction is to be performed; c) mechanically-operable means for altering the relative position of the heat source and the reaction vessel so that reaction vessel first achieves and maintains a desired first temperature in the reaction vessel for starting the carrying out of the biological reaction, and then for altering the relative position of the heat source and the reaction vessel so that reaction vessel then achieves and maintains a second temperate for continuing the carrying out of the biological reaction on the biological material, and d) temperature-sensing means operatively associated with the reaction vessel for controlling the altering of the relative position of the heat source and the reaction vessel so that the

Abstract: The speed of a nucleic acid amplification reaction, such as the Polymerase Chain Reaction (PCR), can be increased by setting the temperature of heat sources above and below the desired denaturation, annealing, and extension temperatures. The reaction mixture is only contacted with the heat sources long enough for the desired temperatures to be reached.