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BP: Fachverband Biologische Physik
BP 34: Imaging
BP 34.1: Talk
Thursday, April 3, 2014, 09:30–09:45, ZEU 250
Fast Frame-Rate FLIM for Applications in Molecular Biology and Photosynthesis Research — •Franz-Josef Schmitt1, Danilo Bronzi2, Marco Vitali1, Cornelia Junghans1, Franco Zappa2, and Thomas Friedrich1 — 1Institute of Chemistry, Biophysical Chemistry, TU Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany — 2Dipartimento di Elettronica Informatica e Bioingegneria, Politecnico di Milano, Piazza Leonardo Da Vinci 25, I-20133 Milano, Italy
A monolithic 64x32 CMOS image sensor for fluorescence detection is presented. Each pixel consists of three 9-bit gated counters and a single-photon avalanche diode (SPAD). Thanks to their inherent digital nature, SPADs have a sensitivity limited only by photon shot noise and therefore single-photon imaging at very high-frame rate is enabled. Moreover, we used a sliding-time window scheme to achieve time-resolved photon detection for measuring the fluorescence lifetime with a temporal resolution down to 200 ps. The described sensor has been used for simultaneous imaging of the fluorescence amplitude and lifetime of a pH-sensitive dual-emission GFP fusion protein (deGFPphSens) expressed in chinese hamster ovary cells (CHO). This allows to monitor over time the pH distribution within individual compartments and organelles of living cells. Additionally, we present fluorescence induction images at the frame-rate of 1 kfps of dark adapted living cells of the blue alga Synechocystis sp. PCC 6803.