[PCR: principles and prospects in clinical biology].

In the short time it has been available, the Polymerase Chain Reaction (PCR) has been rapidly established as a powerful tool for the analysis of genes leading to a wide spread of its application in research. Its basic qualities (sensitivity, specificity and quickness) also offer facilities for its application to the detection and amplification of foreign and aberrant genes. Recent reports have already shown its ability to detect microorganisms and to identify genes related to molecular diseases. Therefore, its application to the diagnosis of infectious and genetic diseases is expected in the next future. However, some problems have to be solved before the use of this technology is routine in clinical chemistry.