Electrochemical detection of DNA triplet repeat expansion.

摘要: Hereditary neurodegenerative diseases are connected with the expansion of trinucleotide repetitive sequences in genomic DNA. Molecular diagnosis these is based on determination triplet repeat length. Currently used methods involve PCR amplification followed by electrophoretic amplicon size. We propose a novel electrochemical technique hybridization target DNA (tDNA) immobilized at magnetic beads reporter probe (RP) complementary to repeats (12 units per RP). The biotin-labeled RP detected via an enzyme-linked assay involving binding streptavidin-alkaline phosphatase conjugate and transformation electroinactive 1-naphthyl phosphate electroactive 1-naphthol. Pyrimidine residues within flanking homopurine (GAA)n tDNA premodified osmium tetroxide, 2,2‘-bipyridine (Os,bipy), introducing labels tDNA. length calculated from ra...