A biotinylated intercalator for selective post-labeling of double-stranded DNA as a basis for high-sensitive DNA assays

For increasing the sensitivity of label-free DNA assays an amplification strategy is proposed based on the synthesis of a proflavine derivative which on the one hand retains its high affinity for double-stranded DNA (dsDNA) intercalation and on the other hand is functionalized via a flexible spacer with biotin moieties. By this, subsequent to the post-labeling of areas with dsDNA, reporter systems such as streptavidin/enzyme conjugates can be bound. Amplified DNA hybridization detection using an oligonucleotide model system, a biotinylated proflavine as intercalator and streptavidin/alkaline phosphatase is demonstrated.