Auto-cycling primer extension for amplified microRNA detection.

The current polymerase-based nucleic acid amplification techniques cannot maintain continuous polymerization reactions unless by changing the temperature or adding additional reagents ( e.g. the second enzyme or betaine), which undoubtedly increases the cost and operation steps. Herein, a new isothermal nucleic acid amplification technique, termed auto-cycling primer extension (APE), is presented. It repeatedly extends short DNA primers to longer DNA hairpins, by combining a DNA-based copy-and-release hairpin (CRH) and palindromic sequence design. The experimental results showed that we could realize the amplification detection of miRNA by a reasonable probe design.