What is the main purpose of polymerase chain reaction (PCR)?

The main purpose of polymerase chain reaction (PCR) is to exponentially amplify specific DNA sequences. PCR is a powerful technique that allows for the rapid and precise duplication of a targeted segment of DNA. This amplification is crucial for various applications in molecular biology, such as cloning, sequencing, and genetic analysis, as it enables researchers to obtain enough DNA for study from very small initial samples.

During the PCR process, a DNA sample undergoes cycles of denaturation, annealing, and extension, involving specific primers that bind to the target DNA sequences. The enzyme DNA polymerase then synthesizes new strands of DNA, leading to a doubling of the target sequence with each cycle. This exponential amplification means that even a minute amount of DNA can be made sufficiently abundant for subsequent analysis or experimentation.

While isolating proteins, identifying mutations, and analyzing entire genomes are important tasks in biotechnology, these do not capture the primary function of PCR itself, which is specifically designed for amplification of DNA sequences. Thus, the amplification of DNA is a distinct and immediate result of the PCR methodology, highlighting its central role in genetic research and diagnostics.