The polymerase chain reaction (PCR) - an in Vitro techniques for producing large amounts of a specific DNA fragment - has rapidly become established as one of the most important, impressive and fascinating methods of molecular biology as well as clinical diagnostics. In the seven years since'the technique was published, it has had a major impact on medical research. However, as there are still problems in instruments, standardized protocols for diagnostic applications and unsolved difficulties to avoid cross-contaminations on the one hand and on the other hand the even present question of how...