Molecular diagnosis. Polymer chain reaction PCR is amplification of of a strand of dna (or rna) establish a sequence making millions of copies thereby helping diagnosis of cancers in early stages, predicting cancer as in braca 1& 11 PCR helps bacteriol & viral infections, and important tool in establishing forensic evidence of a crime.
Amplifying DNA. Pcr is useful for amplifying a dna sample. Molecular analysis can be done with subsequent techniques, such as electrophoresis and dna sequencing.