An apparatus for thermal cycling can transfer heat uniformly and efficiently. The apparatus can be used in a method that reduces condensation on sample wells. The apparatus can also be manufactured to provide uniform configurations. For example, a sample, illustratively for polymerase chain reaction (PCR), in each sample well and the components of the embodiment of the thermal cycler apparatus shown at including a well block, a base plate, a layer of adhesive, a peltier device, another layer of adhesive and a heat sink.