Polymerase Chain Reaction is a laboratory technique used to amplify DNA. The word is spelled as /ˌpɒlɪˌmərˈeɪs tʃeɪn rɪˈækʃən/ in IPA phonetic transcription. The first part of the word, 'polymerase', pronounced as /ˌpɒlɪməˈreɪs/ refers to the enzyme used in the reaction. The second part, 'chain', pronounced as /tʃeɪn/ refers to the DNA strand being copied. The final part 'reaction', pronounced as /rɪˈækʃən/ highlights the chemical process. Despite the complex spelling, Polymerase Chain Reaction is regularly used by scientists to understand the genetic basis of diseases.
Polymerase Chain Reaction (PCR) is a powerful biological technique used to amplify a specific segment of DNA or RNA in large quantities. It is extensively utilized in various fields of research, diagnostics, and genetic engineering due to its precision and sensitivity.
The PCR method involves a series of temperature cycles that facilitate the replication of DNA or RNA strands. The process begins by heating the target sample, denaturing or separating the strands of DNA or RNA, exposing the target sequence. The temperature is then lowered to allow short DNA primers to bind specifically to the target segments. These primers serve as starting points for DNA replication. Following this, the temperature is raised to an optimal range to activate a DNA polymerase enzyme that synthesizes new DNA strands, starting from the primers and extending them along the target sequence. This process generates new complementary DNA strands, resulting in the duplication of the specific target segment.
This exponential amplification process, repeating the temperature cycles over and over, enables the production of millions or billions of copies of the desired DNA or RNA segment within a few hours. The amplified product can then be used for various applications, such as genetic testing, DNA sequencing, identification of pathogens, forensic analysis, and cloning. PCR has revolutionized molecular biology and has become an indispensable tool in the study of genes, genetic diseases, and DNA-based investigations.