Thermocycler temperature variation invalidates PCR results.

Among the factors which have to be optimized to ensure highest sensitivity and specificity of the polymerase chain reaction (PCR) is the processor which enables the automatic performance of the PCR assay. It has to guarantee temperature homogeneity for all samples of an individual run and run-to-run comparability. The following report illustrates that the present generation of PCR processors does not yet fulfill this requirement to satisfaction. It discusses examples of significant performance variations and their consequences for the outcome of the amplification reaction.