Dual amplification of a bio-barcode and auto-cycling primer extension for highly sensitive detection of miRNA.

MicroRNAs (miRNAs) can be used as biomarkers for the diagnosis and therapy of cancers. However, their low abundance and the complex environment in biological samples hinder miRNA detection. A dual amplification strategy based on the bio-barcode technique (BCA) and auto-cycling primer extension (APE) is proposed to detect miRNA targets in complex biological samples. The strategy shows a good sensitivity for miRNA-19a with a detection limit of 50 fM, and can effectively distinguish other similar miRNAs. It provides a new idea to combine nanoparticle-based amplification with nucleic acid-based amplification together for the sensitive detection of nucleic acid targets.