Thermal cycler

Thermal cycler or thermocycler or PCR machine is a laboratory apparatus used for PCR. The device has a thermal block with holes where tubes with the PCR reaction mixtures can be inserted. The cycler then rises and lowers the temperature of the block in discrete, pre-programmed steps.

Modern thermal cyclers are often equipped with hot bonnet, a heated plate that presses against the lids of the reaction tubes. This prevents condensation of water from the reaction mixtures to the insides of the lids and makes it unnecessary to use PCR oil. Some thermal cyclers are equipped with multiple blocks allowing several different PCR reactions to be carried out simultaneously. Also some apparatuses have a gradient function, which allowes different temperatures in different parts of the block. This is particularly useful when testing suitable annealing temperatures for primers. The prices for thermal cyclers start from USD 2500 (in 2004).