Berlin 2012 – scientific programme

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BP: Fachverband Biologische Physik

BP 28: Posters: Imaging

BP 28.2: Poster

Thursday, March 29, 2012, 17:30–19:30, Poster A

Fluorescence spectral coding for identification of molecules at low concentration — •Zdeněk Petrášek, Jens Wiedemann, and Petra Schwille — Biotechnologisches Zentrum, TU Dresden, Tatzberg 47/49, 01309 Dresden, Germany

We investigate how a combination of 2-3 distinct fluorescent dyes could be used to produce multiple spectral codes for unique species identification. As an experimental model we use non-fluorescent beads to which different fluorescent molecules are attached. The emission from immobilized beads is dispersed by a prism and imaged by a camera.

We study how the noise level influences the ability to resolve two different spectra, using both simulations and experiments. The effects of the spectral overlap and of the number of spectral channels were explored. Introducing convenient expressions for the noise level in the spectrum and the difference between two spectra leads to a simple relationship between the spectral difference (which can be calculated from noiseless reference spectra) and the resolvability, defined as a maximum noise level required to guarantee a given success identification rate. Experiments show that the bead autofluorescence, if not exceeding the probe fluorescence, does not prevent correct identification of the spectral code. Initial results of simulations further suggest that finding the bead in the noisy image may be more difficult than identifying its spectral code, once the bead is found.