This product is part of a set of unquenched liquid scintillation counting standards. Unquenched standards are used to optimize liquid scintillation counter settings and to check long term stability of the instrument. Each standard contains PPO/Dimethyl POPOP in scintillation grade toluene, is argone purged, and is flame sealed in a borosilicate ampoule. Each standard has a cap designed for high reflectivity and ease of handling. Pico standards are used for small vial systems.