Tuning direct current streaming dielectrophoresis of proteins

Asuka Nakano, Fernanda Camacho-Alanis, Tzu Chiao Chao, Alexandra Ros

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Dielectrophoresis (DEP) of biomolecules has large potential to serve as a novel selectivity parameter for bioanalytical methods such as (pre)concentration, fractionation, and separation. However, in contrast to well-characterized biological cells and (nano)particles, the mechanism of protein DEP is poorly understood, limiting bioanalytical applications for proteins. Here, we demonstrate a detailed investigation of factors influencing DEP of diagnostically relevant immunoglobulin G (IgG) molecules using insulator-based DEP (iDEP) under DC conditions. We found that the pH range in which concentration of IgG due to streaming iDEP occurs without aggregate formation matches the pH range suitable for immunoreactions. Numerical simulations of the electrokinetic factors pertaining to DEP streaming in this range further suggested that the protein charge and electroosmotic flow significantly influence iDEP streaming. These predictions are in accordance with the experimentally observed pH-dependent iDEP streaming profiles as well as the determined IgG molecular properties. Moreover, we observed a transition in the streaming behavior caused by a change from positive to negative DEP induced through micelle formation for the first time experimentally, which is in excellent qualitative agreement with numerical simulations. Our study thus relates molecular immunoglobulin properties to observed iDEP, which will be useful for the future development of protein (pre)concentration or separation methods based on DEP.

Original languageEnglish (US)
Article number034108
JournalBiomicrofluidics
Volume6
Issue number3
DOIs
StatePublished - Jul 18 2012

Fingerprint

Electrophoresis
Tuning
direct current
tuning
insulators
proteins
Proteins
Immunoglobulin G
molecular properties
Electroosmosis
electrokinetics
Micelles
fractionation
Immunoglobulins
micelles
Computer simulation
simulation
Biomolecules
selectivity
Fractionation

ASJC Scopus subject areas

  • Genetics
  • Molecular Biology
  • Condensed Matter Physics
  • Materials Science(all)
  • Physical and Theoretical Chemistry

Cite this

Tuning direct current streaming dielectrophoresis of proteins. / Nakano, Asuka; Camacho-Alanis, Fernanda; Chao, Tzu Chiao; Ros, Alexandra.

In: Biomicrofluidics, Vol. 6, No. 3, 034108, 18.07.2012.

Research output: Contribution to journalArticle

Nakano, Asuka ; Camacho-Alanis, Fernanda ; Chao, Tzu Chiao ; Ros, Alexandra. / Tuning direct current streaming dielectrophoresis of proteins. In: Biomicrofluidics. 2012 ; Vol. 6, No. 3.
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