Differentiation of Escherichia coli serotypes using DC gradient insulator dielectrophoresis

• Published in: Analytical and bioanalytical chemistry Vol. 406; no. 1; pp. 183 - 192
• Main Authors: Jones, Paul V., DeMichele, Alexa F., Kemp, LaKeta, Hayes, Mark A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2014; Springer; Springer Nature B.V
• Subjects: Analysis; Analytical Chemistry; Bacteria; Biochemistry; Cellular; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Control; Diagnosis; Dielectric properties; Dielectrophoresis; Differentiation; E coli; Electric Conductivity; Electric fields; Electric potential; Electric properties; Electricity; Electrophoresis; Electrophoresis - instrumentation; Electrophoresis - methods; Escherichia coli; Escherichia coli - isolation & purification; Food Science; Foodborne diseases; Identification; Identification and classification; Insulators; Laboratory Medicine; Mass spectrometry; Microfluidic Analytical Techniques - instrumentation; Microfluidics; Microorganisms; Monitoring/Environmental Analysis; Movement; Nanotechnology; Research Paper; Risk factors; Sample preparation; Scientific imaging; Serotyping - instrumentation; Serotyping - methods; United States; USA; Bioanalytical methods; Dielectrophoresis; Electrokinetic separations; Microfluidics
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-013-7437-5

Bacteria play a significant role in both human health and disease. An estimated 9.4 million cases of foodborne illness occur in the United States each year. As a result, rapid identification and characterization of microorganisms remains an important research objective. Despite limitations, selective culturing retains a central role among a cadre of identification strategies. For the past decade, separations-based approaches to rapid bacterial identification have been under investigation. Gradient insulator dielectrophoresis (g-iDEP) promises benefits in the form of rapid and specific separation of very similar bacteria, including serotypes of a single species. Furthermore, this approach allows simultaneous concentration of analyte, facilitating detection and downstream analysis. Differentiation of three serotypes or strains of Escherichia coli bacteria is demonstrated within a single g-iDEP microchannel, based on their characteristic electrokinetic properties. Whole cells were captured and concentrated using a range of applied potentials, which generated average electric fields between 160 and 470 V/cm. Bacteria remained viable after exposure to these fields, as determined by cellular motility. These results indicate the potential g-iDEP holds in terms of both separatory power and the possibility for diagnostic applications.