Essay: The polymerase chain reaction (PCR)…

The polymerase chain reaction (PCR) includes the use of two fragments of DNA, whether they are primers or oligonucleotides, to make two molecules of nucleic acid amplify and therefore synthesis of a specific region of DNA(1). The DNA sample first altered to make the DNA double helix of two single strands(1). This happens by putting the DNA sample in an aqueous environment and heating it at 94??Cbetween30 seconds and five minutes(1). PCR amplification requires specific and precise hybridization process of the primers which comprises specific nucleotide sequences(1). These are in PCR primers and are complementary to either parallel or anti-parallel target sequences of DNA molecules, and it occurs by lowering the temperature to between 40??C and 60??C depending on the design of the primers(1). The amplification product’s length and the specifics of the PCR can be determined by the two primers, while the primers are exactly complementary to the target sequences(1). Some sequence data from the terminal ends of the DNA are needed to design the primer(1). The thermostable DNA polymerase is the second key component of PCR(1). It requires the double standard 3??-hydroxyl terminus (which is the result after the primers have hybridized the target DNA) to the synthesis of a new DNA strand and is complementary to the strand that the primers have hybridized(1). After the hybridization process, the temperature is increased to about 72??C, which is required for thermostable DNA polymerase in order to replicate the DNA strands(1). During the PCR thermocycling, the two strands of the DNA double helix (sense, anti-sense) are copied and amplified(1). Consequently, the target DNA strands are disassociated, allowing both strands of DNA to amplify in the 5?? to 3?? direction(1). The process is repeated several times and the new synthesized double-stranded DNAmolecule is called an amplimer or amplicon(1). It consists of terminal sequences complementary to the utilized primer sequences(1). This amplimer becomes a template for replication in the following rounds of PCR cycling, which results in a huge amplification of the target molecules in each cycle(1).