Bioelectronic detection of point mutations using discrimination of the H63D polymorphism of the Hfe gene as a model

Background: A bioelectronic detection platform has recently been developed that facilitates the detection and characterization of nucleic acids. The D NA chip platform is compatible with homogeneous assays because separate lab eling and wash steps are not required. A one-step, bioelectronic detection assay was developed to genotype patient samples with respect to the H63D po lymorphism of the Hfe gene, associated with hereditary hemochromatosis. Methods and Results: Electrode arrays were modified with DNA capture probes that were perfectly matched to the wild-type or mutant allele of H63D. Amp licons containing the polymorphic site were hybridized with the capture pro bes on the electrode arrays in the presence of electronically labeled repor ter (signaling) probes. Voltammetric analysis of the electrode arrays was c onducted first at ambient temperature and then at elevated temperature. The electronic signal was preferentially diminished at elevated temperature fr om electrodes that hybridized with mismatched target amplicons. Conclusion: An assay for bioelectronic genotyping of the H63D polymorphism was developed and used with six patient specimens to show the feasibility o f this system as a model for point mutation detection.