The High content screening facility (HCS) at FORTH-IMBB started its operation in 2015. It is equipped with a HCS Microscope Operetta (Perkin Elmer). HCS combines the automation of fluorescence microscopy coupled with quantitative image analysis in large scale applications. The image based screening measures a variety of phenotypes in cells, tissues and small animal models. It is suitable for studies aiming to track changes on cellular morphology and behavior due to the effect of a drug or inhibitor. It can measure protein expression and translocation, fluorescence redistribution within the cell, apoptosis, proliferation, viral infection, organelle structure, cell and organ morphology, neurite outgrowth etc.