Dresden 2009 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 38: POSTERS Micro- and Nanofluidics

CPP 38.2: Poster

Donnerstag, 26. März 2009, 17:00–19:30, P3

Reversible single bacterial cell localization in microfluidic PDMS devices — •Lukas Galla, Dominik Greif, Jan Regtmeier, and Dario Anselmetti — Bielefeld University, Experimental Biophysics & Applied Nanoscience, Universitätsstr. 25, 33615 Bielefeld, Germany

For successful optical investigations of bacteria cells it is beneficial to use a method that allows a reversible and defined positioning of single cells at physiological conditions.

Here, we present two approaches for single cell and particle localization in a microfluidic poly(dimethylsiloxane) (PDMS) device. Firstly, in structured microchannels with obstacles at defined positions we used electrokinetic driving forces and electrodeless dielectrophoresis for particle trapping. Secondly, branched channel systems with 1µm-intersection points in combination with hydrostatic flux control also allow an exact positioning of particles. In order to prevent unspecific particle adsorption, the channel surface of both types of PDMS chips was coated with a triblock-copolymer (F108).

The functionality of these two approaches was confirmed in experiments with 1,9µm fluorescent beads followed by successful localizations of bacterial cells (S.meliloti 1021, 0,5µm x 3µm) suspended in culture medium. No reduction of the cell viability was observed. Both approaches demonstrate the efficiency of the single bacterial cell trapping methods and open the way for new designs of single cell experiments.