title: Counter-pressure-assisted ITP with electrokinetic injection under field-amplified conditions for bacterial analysis.
abstract: Counter-pressure was used to extend the duration of field-amplified sample injection in isotachophoresis (FASI-ITP) in order to improve the detection of bacterial cells. Using 0.51-μm negatively charged encapsulated fluorescent beads as a model, the counter-pressure, injection and separation voltages, and times were optimized. Using 6-min 8,963-Pa counter-pressure FASI-ITP injections at -12 kV followed by mobilization of the ITP band with continued injection at -6 kV, the limit of detection (LOD) for Escherichia coli was improved to 78 cells/mL, a factor of 4 when compared with FASI-ITP without counter-pressure.
authors.affiliation: Australia Centre for Research on Separation Science, School of Physical Sciences - Chemistry, University of Tasmania, Hobart, TAS, 7001, Australia.
authors.forename: Sui Ching
authors.initials: SC
authors.lastname: Phung
authors.forename: Yi Heng
authors.initials: YH
authors.lastname: Nai
authors.forename: Mirek
authors.initials: M
authors.lastname: Macka
authors.forename: Shane M
authors.initials: SM
authors.lastname: Powell
authors.forename: Rosanne M
authors.initials: RM
authors.lastname: Guijt
authors.forename: Michael C
authors.initials: MC
authors.lastname: Breadmore
mesh_terms: D058491:Bacterial Load / Q000379:methods*; D002469:Cell Separation / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods*; D004926:Escherichia coli / Q000302:isolation & purification*; D057625:Isotachophoresis / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity