Continuous concentration of bacteria in a microfluidic flow cell using electrokinetic techniques.
A novel method for the concentration of bacterial solutions is presented that implements electrokinetic techniques, zone electrophoresis (ZE) and isoelectric focusing (IEF), in a microfluidic device. The method requires low power (< 3e-5 W) and can be performed continuously on a flowing stream. The device consists of two palladium electrodes held in a flow cell constructed from layers of polymeric film held together by a pressure-sensitive adhesive. Both ZE and IEF are performed with carrier-free solutions in devices in which the electrodes are in intimate contact with the sample fluid. IEF experiments were performed using natural pH gradients; no carrier ampholyte solution was required. Experiments performed in buffer alone resulted in significant electroosmotic flow. Pretreatment of the sample chamber with bleach followed by a concentrated solution of cationic detergent effectively suppressed electroosmotic flow.
Cabrera
C R
CR
Department of Bioengineering, University of Washington, Seattle 98195, USA. cathycab@u.washington.edu
Yager
P
P
D001419:Bacteria / Q000737:chemistry / Q000187:drug effects / Q000302:isolation & purification*; D001431:Bacteriological Techniques / Q000295:instrumentation*; D002473:Cell Wall / Q000737:chemistry; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology; D004586:Electrophoresis / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D004885:Erwinia / Q000737:chemistry / Q000187:drug effects / Q000302:isolation & purification; D007091:Image Processing, Computer-Assisted; D007202:Indicators and Reagents; D007525:Isoelectric Focusing / Q000295:instrumentation*; D008856:Microscopy, Fluorescence; D008904:Miniaturization; D012996:Solutions; D013499:Surface Properties
D002593:Cetrimonium Compounds; D003902:Detergents; D007202:Indicators and Reagents; D012996:Solutions; D000077286:Cetrimonium