Detection of Single Nucleotide Polymorphisms Using Selective Incorporation of Biotin in DNA Strand and Subsequent Enzymatic Detection at Pencil Electrode

Enzyme-linked electrochemical assay using DNA labeling by biotin followed by binding of enzyme-streptavidin conjugates has been found to be a potent tool for DNA diagnostic. This approach brings a special advantage of signal amplification due to the fact, that only very small number of enzymatic labels can produce a number of molecules of an electrochemically detectable product from an inactive substrate to obtain sufficiently strong signal. A new way of using of this technique combined with selective primer extension reaction designed for the detection of single nucleotide polymorphism is presented here. The assay was combined with measurements at a pencil graphite electrode, which is a very practical tool for potential clinical applications due to its cheapness and disposability.