Electrochemical analysis of the self-complementary B-DNA decamer d(CCAGGCCTGG)

The self-complementary decamer d(CCAGGCCTGG), native and denatured calf thymus DNAs were studied by means of differential pulse polarography with the DME and by cyclic voltammetry with the HMDE. The decamer (which represents one turn of the DNA double helix in the B form) produced cathodic and anodic signals similar to those yielded by high-molar mass DNAs. By measuring the anodic peak (due to guanine residues), it was possible to detect the decamer at subnanomolar concentrations by adsorptive stripping cyclic voltammetry at relatively short waiting times. The high sensitivity of the electrochemical analysis for small changes in the DNA double helix observed earlier in high-molar mass DNAs, together with the low requirements for the amount of the analyzed decamer sample, suggest that electrochemical techniques may become useful also in oligonucleotide studies.