In this project we study the feasibility of using quantum entanglement of light beams to diagnose brain tissue for disease (Alzheimers, cancer). The samples are provided by collaborators at City College of New York. The optical research and analysis will be conducted at Colgate. The experiment consists of preparing photon pairs in a quantum-entangled state. We then pass one or both photons through a tissue sample and analyze the loss of entanglement.