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Updated: Jun 29, 2026

High Throughput MicroRNA Profiling: Optimized Multiplex qRT-PCR at Nanoliter Scale on the Fluidigm Dynamic ArrayTM IFCs
Published on: August 3, 2011
Highly sensitive, selective, and rapid detection of miRNA-21 using an RCA/G-quadruplex/QnDESA probing system
Tasnima Alam Asa1, Guralamatta Siddappa Ravi Kumara1, Young Jun Seo1
1Department of Chemistry, Jeonbuk National University, Jeonju 561-756, Republic of Korea. yseo@jbnu.ac.kr.
Abstract:
In this study we developed a very simple and rapid miRNA 21 detection system using a novel quinolinium diethylamino salicylaldehyde (QnDESA) probe for sensing the 22AG hybrid G-quadruplex with a single-step rolling circle amplification (RCA) reaction. We synthesized a circular DNA padlock template containing a sequence complementary to the 22AG hybrid G-quadruplex, used SplintR ligase to ensure perfect hybridization with miRNA 21, applied this circular DNA and phi-29 DNA polymerase for tandem amplification of the 22AG hybrid G-quadruplex sequence, and then probed the product using QnDESA. This combination of RCA-G-quadruplex and QnDESA allowed the rapid (1 h) and simple one-pot detection of miRNA 21 based on a change in fluorescence. In addition, this system displayed high sensitivity (limit of detection: 1.37 fM) and selectivity. This probing system should also be useful for identifying a diverse range of DNA- and RNA-based biomarkers.

