[Polymerase chain reaction: use in microbiological diagnosis]

The discovery of the polymerase chain reaction (PCR) enables the detection of just a few target gene copies present in almost every kind of tissue. The PCR technique uses two separated specific DNA-sequences for identification of a desired genetic sequence. This identification is followed by an almost unlimited production of the specific target gene sequence by a heat stable DNA-polymerase. The PCR technique will revolutionize several diagnostic areas, and especially the identification of virus, fungi and slowly growing bacteria will benefit from this new genetic technology. The impressive sensitivity is, however, the greatest pitfall of the technique, as just a few contaminating DNA fragments can initiate a false positive result. Great care is therefore needed when designing a PCR laboratory, as well as high demands upon the motivation and technical skills of the personnel involved. PCR is so far limited to research, but is expected to be released for routine diagnostic purposes in 1993.