ASCP Molecular Biology MB Technologist Practice Exam – Complete Prep 2026

When working with non-proofreading DNA polymerases, maintaining a low concentration of dNTPs is essential for improving fidelity during DNA amplification. The recommended concentration range of 0.01-0.05 mM helps reduce the frequency of incorporation errors that can occur due to the lack of a 3' to 5' exonuclease proofreading activity. Lowering the dNTP concentration minimizes the chances of misincorporation of nucleotides, as it decreases the likelihood of the polymerase skipping or inaccurately incorporating nucleotides under conditions of high dNTP concentration.

In contrast, higher concentrations of dNTPs can lead to increased error rates, especially when using enzymes that do not possess proofreading capabilities. Therefore, opting for a much higher concentration than the recommended range could result in diminished fidelity, leading to the amplification of incorrect sequences. This emphasis on lower dNTP concentrations aligns with best practices in PCR and other amplification techniques when fidelity is a priority.