Statistical Methods for the Determination of the Number of Independent Fluorescent Emitters in Living Cells.

Fluorometric experiments were performed on single living cells and emission spectra were recorded for natural cell fluorescence and metabolization of benzo-pyrene. A model for the fluorometric response was proposed and its validity tested. This model was used together with multivariate statistical methods to find the number of independent fluorescent emitters present in the cells. The chi-square statistic was calculated for the distributions of the deviations of the recorded data from approximated values obtained by constructing low-rank matrix approximations. The method was superior to the involving eigenanalysis and was shown to give good results for single cell recordings.