Quantification of frap experiments in live cell image sequences by combining segmentation and registration

Fluorescence recovery after photobleaching (FRAP) is an important technique for analyzing subcellular processes in living cells. To quantify the acquired data, the fluorescence signal within the cytoplasm and the nucleus of a target cell needs to be determined at each time point. However, the movement and deformation of the cell as well as low contrast render manual and automatic analysis difficult. To quantify FRAP experiments we have developed an approach for the segmentation of the cytoplasm and the nucleus of cells in dynamic microscopy image sequences which combines level set segmentation and image registration. Our approach has been successfully applied to images from FRAP experiments and an experimental comparison with manual expert segmentation has been carried out.