Highly sensitive detection of MUC1 by microchip electrophoresis combining with target recycling amplification and strand displacement amplification

Abstract

Mucin 1 (MUC1) is usually overexpressed in a variety of malignant tumors, and quantitative analysis of MUC1 plays an important role in the early diagnosis of cancer. In this work, a highly sensitive MUC1 assay was developed by integrating microchip electrophoresis (MCE) with target recycling amplification (TRA) and strand displacement amplification (SDA). Specifically, the presence of MUC1 can trigger the exposure of the designed hairpin probe (HP) to initiate SDA and an amplified amount of ssDNA is produced finally. The amount of these ssDNA can be detected by MCE, then the concentration of MUC1 can be obtained through the correlation between MUC1 concentration and ssDNA concentration. The experimental results show that the MCE signal had a good linear relationship with MUC1 concentration in the range of 1.0 pg/mL - 1.0 × 10³ pg/mL with a low limit of detection of 0.23 pg/mL under the optimal conditions (S/N = 3). Additionally, the assay had been successfully applied to detect MUC1 in biological samples with satisfactory results, providing an alternative assay for the detection of other tumor markers owing to the high sensitivity, high selectivity, simple operation and low sample consumption.

Keywords: Isothermal amplification; MUC1; Microchip electrophoresis; Nucleic acid.