Dielectrophoretic separation of bacteria using a conductivity gradient

• Published in: Journal of biotechnology Vol. 51; no. 2; pp. 175 - 180
• Main Authors: Markx, Gerard H., Dyda, Penelope A., Pethig, Ronald
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.11.1996; Amsterdam Elsevier; New York, NY
• Subjects: Bacillus subtilis; Bacillus subtilis - isolation & purification; Bacteria; Bacteria - isolation & purification; Biological and medical sciences; Biotechnology; Cell separation; Conductivity; Dielectrophoresis; Electric Conductivity; Electrophoresis - instrumentation; Electrophoresis - methods; Escherichia coli; Escherichia coli - isolation & purification; Fundamental and applied biological sciences. Psychology; Methods. Procedures. Technologies; Micrococcus luteus; Micrococcus luteus - isolation & purification; Others; Various methods and equipments; Conductivity; Bacteria; Cell separation; Dielectrophoresis; Gradient; Bacillus subtilis; Escherichia coli; Bacillaceae; Micrococcus luteus; Separation method; Bacillales; Micrococcales; Micrococcaceae; Technique; Enterobacteriaceae
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/0168-1656(96)01617-3

Dielectrophoresis, the lateral motion induced on particles by non-uniform electric fields, is a sensitive function of the electrical conductivity of the particle suspending medium. This dependence is exploited in a new technique for separating bioparticles from suspended mixtures. The bioparticles are first immobilised by positive dielectrophoresis at electrodes in a separation chamber, and the conductivity of the liquid flowing through the chamber is then gradually and continuously increased so as to produce a conductivity gradient with time. The bioparticles are released from the electrodes according to their own dielectric properties and as a function of flow rate and medium conductivity. This is demonstrated for pure suspensions and mixtures of the bacteria Bacillus subtilis, Escherichia coli and Micrococcus luteus.