Detection of Escherichia coli by capillary electrophoresis assisted by large volume sample stacking and nicking endonuclease signal amplification

Zhaohui Chu; Jingyi Chen; Jingzi Zhang; Qihui Xie; Fan Zhang; Qingjiang Wang

doi:10.1016/j.chroma.2023.464275

Detection of Escherichia coli by capillary electrophoresis assisted by large volume sample stacking and nicking endonuclease signal amplification

J Chromatogr A. 2023 Sep 13:1706:464275. doi: 10.1016/j.chroma.2023.464275. Epub 2023 Aug 2.

Authors

Zhaohui Chu¹, Jingyi Chen¹, Jingzi Zhang¹, Qihui Xie¹, Fan Zhang², Qingjiang Wang³

Affiliations

¹ School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China.
² School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China. Electronic address: fzhang@chem.ecnu.edu.cn.
³ School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China. Electronic address: qjwang@chem.ecnu.edu.cn.

PMID: 37542930
DOI: 10.1016/j.chroma.2023.464275

Abstract

Efficient, accurate and economical detection of pathogenic bacteria is crucial in ensuring food safety and preventing foodborne illnesses. In this study, a capillary electrophoresis coupled laser-induced fluorescence assay (CE-LIF) was developed for the detection of Escherichia coli (E. coli) by detecting its specific DNA. The CE-LIF was assisted by both online enrichment and offline amplification to improve the detection sensitivity of bacterial DNA. Here the online amplification was performed by large volume sample stacking (LVSS), while the offline amplification was nicking endonuclease signal amplification (NESA). Under the optimal experimental conditions, the detection limit of bacterial target DNA was 2.5 fM, and the conversion concentration of E. coli was 3 CFU · mL^-1. The method had been applied to the detection of commercially available skim milk samples with good results, which proved that it could be used as an effective tool for food and environmental bacteria monitoring.

Keywords: Capillary electrophoresis; E. coli; Large volume sample stacking; Nicking endonuclease signal amplification.

MeSH terms

DNA*
DNA, Bacterial
Electrophoresis, Capillary / methods
Escherichia coli* / genetics

Substances

DNA
DNA, Bacterial