The DIAPRECA project is aimed at exploiting conjointly or consecutively optical microscopy exploration techniques such as reflectance and Raman in a perspective of a better early and in vivo discrimination between healthy, precancerous and cancerous tissues. DIAPRECA brings together the laboratories LTSI-INSERM U 642, ProCadec-CNRS 6164, IGDR-CNRS 6061 of the university of Rennes 1, the service of gastroenterology university hospital of Brest and the company Mauna Kea Technologies. This project covered both aspects of dedicated instrument and software design and ex vivo and in vivo experiments.