Deoxynucleotides (dNTPs) may bind Mg ions and thus affect the concentration of free magnesium ions in the reaction. In addition, excessive amounts of dNTPs can increase the error rate of DNA polymerase and even inhibit the reaction. An imbalance in the proportion of the four dNTPs can result in misincorporation into the newly formed DNA strand and contribute to a decrease in the fidelity of DNA polymerase.