There exist very few techniques for studying a group of cells containinga large number compared to a single cell but small compared to a wholetissue. This implies that statistics are exceedingly difficult to obtainfrom measurements of individual cells. Microfluidics provides a way toamend this by allowing ways to observe individual cells and automatesuch measurements. The aim in this project is to develop a cellmanipulation platforms based on microfluidics techniques developed inour lab, while answering relevant biological questions.The first question concerns Sickle Cell Anemia, a genetic disease forwhich no treatment exists. We will study the polymerization ofhemoglobin within red blood cells, as they are submitted to cycles ofoxygenation and deoxygenation. Quantitative measurements of the responseof the cells to oxygen variations will allow physiological conditions tobe simulated, including in the presence of therapeutic candidates orother biological agents.The second question concerns the motility of adherent cells in athree-dimensional environment. This question will be to understand themigration of cells in a 3D gradient of chemo-attractant, as well asgradients of rigidity of the environment. This part will require thedevelopment of new technological tools which can later be applied to awide range of biological problems. The long term aim is to replace thecurrent tools of biological labs with miniaturized and integrated lab ona chip devices.