Quest Diagnostics began trading in the UK in 1996 and has its major UK laboratory in West London. This state-of-the-art, purpose built laboratory is open seven days a week and undertakes both diagnostic and clinical trials testing.

In May 2001 Quest Diagnostics also opened a laboratory in Central London, located at 10 Upper Wimpole Street, dedicated to providing a fast turnaround service for all routine testing to Central London healthcare providers. The Upper Wimpole Street premises include a walk-in patient service centre where a phlebotomy service is provided.

Additionally, daily flights to Quest Diagnostics US laboratories, including the prestigious Nichols Institute, provide access to a wide network of esoteric tests.

Quest Diagnostics takes a flexible approach to providing a wide range of customers with services tailored to meet their individual needs. Customers include NHS Trust Hospitals, NHS GPs, private hospitals, private physicians and occupational health and wellness companies. An extensive test menu allows Quest Diagnostics to provide services ranging from referrals testing packages to the management of laboratories.

Delivery of results is tailored to suit customers' requirements, with electronic delivery becoming increasingly popular.