Palo Verde Laboratory, 1255 W Washington St, Tempe, AZ 85288, US

With a 120,000-square-foot laboratory that is the largest in Arizona, Sonora Quest Laboratories is an integrated laboratory system that serves more than 5,000 clients throughout the state. Its clients include hospitals, physicians and managed care organizations and employers. The company performs more than 30,000 diagnostic tests on a typical day and each year it conducts more than 14 million laboratory tests, 7,500 cytogenetics tests and 90,000 substance abuse tests. Its services include cardiovascular testing, chlamydia testing, HIV testing and prenatal testing. Sonora Quest Laboratories has headquarters in Tempe, Ariz. It is a subsidiary of both Quest Diagnostics and Banner Health System.