ProStack (Processing of Stacks) is a platform for image processing and analysis. It implements various image processing methods as separate modules, that can be joined in a complex image processing scenario by use of a graphical user interface. This video demonstrates the workflow for extraction of quantitative information on gene expression from confocal images. ProStack home page: urchin.spbcas.ru/downloads/ProStack/ProStack.htm Download:sourceforge.net/projects/prostack/