dNTP mix is a premixed solution containing the sodium salts of dATP. dCTP, dGTP, and dTTP, each at a concentration of 2.5 mM in H₂O; the total concentration of nucleotides, therefore, is 10 mM (pH 7.5). One microliter of the dNTP mix into a 50 µl reaction will give a final dNTP concentration of 200 µM.