Alexandria Real Estate Equities, Inc. is a real estate investment trust (REIT). The Company is an owner and REIT, and life science real estate company, focused on science-driven cluster development through the ownership, operation, management, selective acquisition, development, and redevelopment of properties containing life science laboratory space. The Company is a provider of real estate, technical infrastructure, and services to the life science industry. Client tenants include institutional (universities and independent non-profit institutions), pharmaceutical, biotechnology, medical device, product, and service entities and government agencies, , medical device companies, industrial biotech companies, venture capital firms, and life science product and service companies. As of December 31, 2012, the Company�s operating properties were approximately 93.4% leased.