Polarography phase-sensitive detection

The segments of dh DNA with distorted conformation desorb from the mercury electrode at the potentials by c. 0.2-0.3 V more negative than are the potentials of the peak 1 [102]. This desorption results in an appearance of the peak 2 on a.c. polarograms, which can be detected only for carefully isolated high-molecular mass nucleic acids and with the aid of in-phase component of phase-sensitive a.c. polarography. Peak 2 occurs at still more positive potentials than the peak 3 yielded by the corresponding ss nucleic acids [102]. 

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