title: Flexible planar microfluidic chip employing a light emitting diode and a PIN-photodiode for portable flow cytometers.
abstract: Detection of fluorescence particles is a key method of flow cytometry. We evaluate the performance of a design for a microfluidic fluorescence particle detection device. Due to the planar design with low layer thicknesses, we avoid optical components such as lenses or dichroic mirrors and substitute them with a shadow mask and colored film filters. A commercially available LED is used as the light source and a PIN-photodiode as detector. This design approach reduces component cost and power consumption and enables supplying the device with power from a standard USB port. From evaluation of this design, we obtain a maximum particle detection frequency of up to 600 particles per second at a sensitivity of better than 4.7 × 10(5) MESF (molecules of equivalent soluble fluorochrome) measured with particles for FITC sensitivity calibration. Lowering the flow rate increases the instrument sensitivity by an order of magnitude enabling the detection of particles with 4.5 × 10(4) MESF.
authors.affiliation: Light Technology Institute, Karlsruhe Institute of Technology, Kaiserstr. 12 Geb. 30.34, Karlsruhe, Baden-Württemberg 76131, Germany. siegfried.kettlitz@kit.edu
authors.forename: Siegfried W
authors.initials: SW
authors.lastname: Kettlitz
authors.forename: Sebastian
authors.initials: S
authors.lastname: Valouch
authors.forename: Wiebke
authors.initials: W
authors.lastname: Sittel
authors.forename: Uli
authors.initials: U
authors.lastname: Lemmer
mesh_terms: D004581:Electronics; D004867:Equipment Design; D005434:Flow Cytometry / Q000295:instrumentation*; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D010316:Particle Size; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D016650:Fluorescein-5-isothiocyanate