An Aptamer-Based Competitive Fluorescence Quenching Assay for IgE

Abstract

A simple competitive fluorescence quenching assay based on aptamer was developed for IgE detection. Two DNA probes were used. One is 5′-end fluorescein-labeled IgE aptamer; the other is 3′-end DABCYL-labeled short DNA, which would hybridize with IgE aptamer to quench the fluorescence. In the presence of IgE, the aptamer-IgE complex formed is strong enough to prevent the short DNA probes hybridizing with the bounded aptamer probes, which results in the less decrease of fluorescence intensity. The signal change was found to be proportional to the concentration of IgE from 0.35 to 35 nM with a detection limit of 0.17 nM.

Keywords:

• Aptamer
• Fluorescence assay
• IgE detection

Acknowledgments

This research was supported by the National Natural Science Foundation of China (Grant No. 20675028) and the Youth Foundation of Huizhou University (No. C5090202).