Biophysical separation of Staphylococcus epidermidis strains based on antibiotic resistance

Paul V. Jones, Shannon Huey, Paige Davis, Ryan Yanashima, Ryan McLemore, Alex McLaren, Mark Hayes

Research output: Contribution to journalArticlepeer-review

34 Scopus citations


Electrophoretic and dielectrophoretic approaches to separations can provide unique capabilities. In the past, capillary and microchip-based approaches to electrophoresis have demonstrated extremely high-resolution separations. More recently, dielectrophoretic systems have shown excellent results for the separation of bioparticles. Here we demonstrate resolution of a difficult pair of targets: gentamicin resistant and susceptible strains of Staphylococcus epidermidis. This separation has significant potential implications for healthcare. This establishes a foundation for biophysical separations as a direct diagnostic tool, potentially improving nearly every figure of merit for diagnostics and antibiotic stewardship. The separations are performed on a modified gradient insulator-based dielectrophoresis (g-iDEP) system and demonstrate that the presence of antibiotic resistance enzymes (or secondary effects) produces a sufficient degree of electrophysical difference to allow separation. The differentiating factor is the ratio of electrophoretic to dielectrophoretic mobilities. This factor is 4.6 ± 0.6 × 10(9) V m(-2) for the resistant strain, versus 9.2 ± 0.4 × 10(9) V m(-2) for the susceptible strain. Using g-iDEP separation, this difference produces clear and easily discerned differentiation of the two strains.

Original languageEnglish (US)
Pages (from-to)5152-5161
Number of pages10
JournalThe Analyst
Issue number15
StatePublished - Aug 7 2015

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Environmental Chemistry
  • Spectroscopy
  • Electrochemistry


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