title: Design of an interface to allow microfluidic electrophoresis chips to drink from the fire hose of the external environment.
abstract: An interface design is presented that facilitates automated sample introduction into an electrokinetic microchip, without perturbing the liquids within the microfluidic device. The design utilizes an interface flow channel with a volume flow resistance that is 0.54-4.1 x 10(6) times lower than the volume flow resistance of the electrokinetic fluid manifold used for mixing, reaction, separation, and analysis. A channel, 300 microm deep, 1 mm wide and 15-20 mm long, was etched in glass substrates to create the sample introduction channel (SIC) for a manifold of electrokinetic flow channels in the range of 10-13 microm depth and 36-275 microm width. Volume flow rates of up to 1 mL/min were pumped through the SIC without perturbing the solutions within the electrokinetic channel manifold. Calculations support this observation, suggesting a leakage flow to electroosmotic flow ratio of 0.1:1% in the electrokinetic channels, arising from 66-700 microL/min pressure-driven flow rates in the SIC. Peak heights for capillary electrophoresis separations in the electrokinetic flow manifold showed no dependence on whether the SIC pump was on or off. On-chip mixing, reaction and separation of anti-ovalbumin and ovalbumin could be performed with good quantitative results, independent of the SIC pump operation. Reproducibility of injection performance, estimated from peak height variations, ranged from 1.5-4%, depending upon the device design and the sample composition.
authors: Department of Chemistry, University of Alberta, Edmonton, Canada.
authors: S
authors: S
authors: Attiya
authors: A B
authors: AB
authors: Jemere
authors: T
authors: T
authors: Tang
authors: G
authors: G
authors: Fitzpatrick
authors: K
authors: K
authors: Seiler
authors: N
authors: N
authors: Chiem
authors: D J
authors: DJ
authors: Harrison
mesh_terms: D000818:Animals; D001120:Arginine / Q000032:analysis; D001331:Automation; D004586:Electrophoresis / Q000295:instrumentation* / Q000379:methods; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D016650:Fluorescein-5-isothiocyanate / Q000032:analysis; D005456:Fluorescent Dyes / Q000032:analysis; D008832:Microchemistry / Q000295:instrumentation*; D008904:Miniaturization; D009862:Online Systems; D010047:Ovalbumin / Q000032:analysis; D010649:Phenylalanine / Q000032:analysis; D015203:Reproducibility of Results; D012212:Rheology
chemical_list: D005456:Fluorescent Dyes; D010649:Phenylalanine; D010047:Ovalbumin; D001120:Arginine; D016650:Fluorescein-5-isothiocyanate