Berlin 2005 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
AKB: Biologische Physik
AKB 200: Poster Session II
AKB 200.61: Poster
Dienstag, 8. März 2005, 17:00–19:00, Poster TU C
Response of ion currents across the cell membrane to excitation with high-frequency electrical fields — •Michael Olapinski1, Andrea Brüggemann2, Michael George2, Stephan Manus1, Niels Fertig2, and Friedrich C. Simmel1 — 1Sektion Physik and Center for Nanoscience, Universität München, Geschwister-Scholl-Platz 1, 80539 München — 2Nanion Technologies GmbH, Pettenkoferstr. 12, 80336 München
Due to the intrinsically large RC time constants of the measurement setup, classical patch-clamp techniques are limited in time resolution. They are therefore not suitable for the application of high-frequency (HF) electrical signals and for the study of fast processes coupling to the ion transport dynamics.
Our setup combines a patch-clamp on-a-chip system with an open-end coaxial probe that is positioned a few tenths of a millimeter above the investigated cells. Ion currents through the cell membrane are measured in whole-cell configuration while high-frequency fields are applied at frequencies between 100 MHz and 50 GHz and at power levels up to +25dBm.
Preliminary results obtained on rat basophil leukaemia (RBL) cells containing potassium channel Kir2.1 suggest that the ion current is sensitive to the applied HF field in specific frequency ranges and depends on the presence of potassium ions and the applied membrane potential. Temperature measurements of the solution do not show any significant temperature rise.