Chemiluminescence, or chemical light, is the principle behind the glow sticks (also known as light sticks) used at rock concerts and as quick tools to grab when the electricity goes out. But they can also be used to diagnose diseases by identifying concentrations of biological samples. A new mechanism developed by Tel Aviv University researchers produces a 3,000-times-brighter, water-resistant chemiluminescent probe with particular application to medical and cancer diagnosis.