Question

identify the necessary ingredients for a successful PCR reaction. Also describe the feature needed in the DNA polymerase for the reaction to be successful.

Answer 1

The polymerase chain reaction is used for the making a copies of the DNA molecules.The necessary ingredients for a successful PCR reaction are -

a. Template DNA - It contains the target region for the primers to bind and DNA synthesis.

b .Forward and reverse primer -locate the start nucleotide point for  the DNA synthesis.

c. dNTP - deoxynucleotide triphosphate (building blocks of DNA)

d .Taq Polymerases (DNA polymerase) -used for amplification of the DNA by using template DNA.

The DNA polymerase has following features which makes the PCR reaction successful-

a. The DNA polymerase is highly specific to the DNA synthesis when added just before the start of the PCR reaction,which reduces the risk of mistargated primer binding and primer dimer formation.

b.The Taq DNA polymerase is extremely stable on the high temperature as it is obtained from the thermophilic bacteria.It prevents the denaturation of the DNA strand and secondary structure formation at 90 degree C which helps in obtaining the intact DNA amplification.

c.The Taq DNA polymerases has the strong proofreading capability or 3'-5' exonuclease activity .It proofreads the DNA sequence which is being synthesized and removes the misincorporated nucleotides which results into the low error sequence of the DNA.

d.The processivity of the Taq DNA polymerases is high ,it processes the large number of nucleotides in single binding which causes the high rate and speed of the synthesis.Thus, it takes less time in amplification of the long DNA templates.