Berlin 2008 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 22: POSTERS Micro- and Nanofluidics

CPP 22.19: Poster

Wednesday, February 27, 2008, 16:00–18:30, Poster A

Native UV laser induced fluorescence detection for single cell analysis in a hybrid PDMS-Quartz microfluidic chip — •Dominik Greif, Alexandra Ros, and Dario Anselmetti — Experimental Biophysics & Applied Nanoscience, Bielefeld University, Universitaetsstr. 25, 33615 Bielefeld, Germany

Single cell analysis promises individual expression studies, which are not limited by ensemble averaging effects. Label free detectors based on UV laser induced autofluorescence (UV-LIF) of aromatic amino acids are a valuable extension of the single cell approach.

Here, we present an extension of our previous studies on single cell analysis with native label-free UV-LIF detection [2], in order to improve separation efficiency and detection sensitivity. We reduced the background fluorescence by the fabrication of new PDMS-Quartz-Window-chips (PQW-chips) by at least 75 percent. These PQW-chips integrate fused silica windows in the PDMS-microdevice at the point of detection. Furthermore, the fluorescence intensity of Trp was investigated for different pH values of the separation buffer. Based on these improvements we exemplarily present single cell protein electropherograms from spodoptera frugiperda (Sf9) cells.

[1] W. Hellmich, D. Greif, C. Pelargus, D. Anselmetti, A. Ros, J. Chromatogr. A 1130 (2006) 195. [2] W. Hellmich, C. Pelargus, K. Leffhalm, A. Ros, D. Anselmetti, Electrophoresis 26 (2005) 3689.