CALIPSO is composed of four scientific work packages aiming at obtaining an integrative model of acclimation in photosynthetic organisms and translation into crops and biotechnologically relevant alga. They apply state-of-the-art technology from various disciplines of life science ranging from molecular biology and genetics (generation of transgenic algae and plants, gene expression analysis), cell biology (protein localization, Ca2+ live cell imaging), biochemistry (kinase/phosphatase assays, proteomics, protein purification), high throughput biology (GC-MS based metabolomics and Mass-western analysis) to bioinformatics (motif and domain identification, network analysis) and evolutional biology (tracing the evolution of key proteins to understand conserved functions across different species). In CALIPSO this is achieved in a collaborative effort within four highly interconnected scientific work packages, complemented by training and management work packages. Most employees of CALIPSO are active within more than one of the four scientific WPs.