Tcspcfit - A Matlab package for fitting multiexponential fluorescence decay curves
Time correlated single photon counting (TCSPC) is a widely used tool for measuring the lifetimes of fluorescent molecules. To obtain the fluorescence lifetimes from the measured data, one has to apply a non-linear fit routine to the measured fluorescence data and Instrumental Response Function (IRF).
The Matlab package Tcspcfit provides a powerful and sophisticated tool for fitting multi-exponential decays to measured data against a measured IRF. It contains an automatic initial guess value estimator, which makes the provision of initial guess values obsolete. It fits not only decay times, but also offset and color shift (time shift between fluorescence and IRF). It uses an efficient Nelder-Meade simplex algorithm. It offers least squares and maximum likelihood fits. Detailed information behind the fitting mathematics can be found in:
"Fast fitting of multi-exponential decay curves"
J. Enderlein, R. Erdmann
Optics Communications 134(1-6), 1997, pp.371-8
Although there is no manual to the package, the package files contain enough explaining text (simply type, in Matlab, "help tcspcfit"), so that somebody familiar with TCSPC-experiments should be able to use them without difficulty. The package can be downloaded here in zipped format. You can find more information about TCSPC and related products at PicoQuant GmbH.