Chip elements for fast thermocycling

The polymerase chain reaction (PCR) is a molecular biological method for the in vitro amplification of nucleic acid molecules. Using a cycle of thermally controlled reaction steps, a start molecule can be multiplied cycle by cycle up to factors of about 10(9). An efficient PCR relies particularly on fast heating and cooling processes, high temperature uniformity and small-sized devices. Here miniaturized thermocyclers show important advantages. Silicon-based thermocyclers with one, two, and ten chambers for volumes in the microlitre range have been prepared in order to realize fast thermocycling by high heating and cooling rates. The presented chip elements have dimensions of 20 mm x 18 mm and a weight of about 1 g. (C) 1997 Elsevier Science S.A.