Puracyp is a privately held company that began operations in 1993 when it focused on the distribution of monospecific inhibitory antibodies to several human P450 enzymes. It also held contracts with pharmaceutical companies to custom manufacture hum liver fractions. The company rapidly changed its focus and Puracyp received several million dollars in SBIR funding and private investment to develop stable cell lines containing reporter gene constructs. The first of these products was introduced in 2003 and in 2005 Puracyp received exclusive global license for the use of the human PXR/SXR gene sequence for screening xenobiotics