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BP: Fachverband Biologische Physik

BP 12: Posters: New Technologies

BP 12.1: Poster

Monday, March 14, 2011, 17:15–20:00, P3

Spectrally-resolved identification of fluorescent probes at low concentration — •Jens Wiedemann, Zdeněk Petrášek, and Petra Schwille — Biophysics group, Biotechnologisches Zentrum, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany

We present a simple technique for the detection and identification of a large number of spectrally distinct fluorescent probes at low concentration, based on the differences in their emission spectrum shape. The fluorescence originating from immobilized beads containing a low number (100s or less) of fluorescent molecules is dispersed by a prism and imaged by a CCD camera. A line illumination of the sample leads to a pseudo-image with one coordinate corresponding to the spatial dimension and the other coordinate to the emission wavelength. To image the whole field of view, the excitation line has to be scanned across the sample.

The beads present within the illuminated line are automatically identified and their spectrum compared with a set of reference spectra. We investigate both theoretically and experimentally the limits of the ability to correctly identify the spectrum, depending on the spectral overlap and the noise level. The possibility of resolving beads with spectral signatures created by a combination of different fluorophores, including different concentration ratios, and the effects of the interference of the bead autofluorescence, are being explored.