PCR Techniques · Pathology

What is the primary purpose of adding Magnesium Chloride ($MgCl_2$) to a PCR master mix?

To act as a pH buffer for the reaction
To serve as a cofactor for Taq DNA polymerase
To prevent the degradation of dNTPs
To lower the melting temperature of the primers

Show answer and explanation

Correct answer: To serve as a cofactor for Taq DNA polymerase

Magnesium ions act as a necessary cofactor for DNA polymerase activity and influence primer annealing. Excessive magnesium can decrease specificity, while insufficient magnesium can lead to low yield.

Difficulty: Medium Question 4 of 20

Practice all 20 PCR Techniques questions

What is the primary purpose of adding Magnesium Chloride ($MgCl_2$) to a PCR master mix?

More PCR Techniques questions