Affinity Group Limited

Quest Diagnostics – Corporate overview

Quest Diagnostics, with its 42,000 employees and network of laboratories around the world, is renowned throughout the medical profession and pharmaceutical industry for providing a first class clinical trial and diagnostic testing service for pharmaceutical and biotechnology companies, hospitals, physicians, clinics and corporate health management companies.

Quest Diagnostics is the de facto global leader of clinical laboratory services, with the largest laboratory database in the world, carrying out personal health testing on more than 150 million patients annually.. The company aims to give client companies in US, EU and emerging markets around the world a first-class service, in all diagnostic areas, including more esoteric lines such as genetics and molecular diagnostics.

Located in 40 laboratories across the globe (but drawing on a network of over 150 rapid response labs within the global Quest Diagnostics organisation as well as having links to key independent experts) the company offers services in biochemistry, cytology, endocrinology, flow cytometry, haematology, histology, immunology, microbiology, toxicology and serology on a local basis for most diagnostic and pharmaceutical clients. In addition, via one of Quest Diagnostics subsidiary companies, Nichols Institute, Quest Diagnostics provides access to virtually every esoteric test known and can also lead the transfer of academic technological innovation to clinical testing.

Quest Diagnostics in the UK

Quest Diagnostics began trading in the UK in 1999 and has its major UK laboratory in Heston, 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 opened a laboratory in Central London, located at 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 (blood drawing) service is provided.
Quest Diagnostics also has offices in Hounslow.


Following successful negotiations Quest Diagnostics assumed responsibility for the provision of Pathology Services to the West Middlesex University Hospital from September 1st 2007.


Within the UK, Quest Diagnostics has two business units – UK Diagnostics, which provides testing services to private & NHS hospitals, GPs, clinics and occupational health & wellness companies; and the Clinical Trials business unit (part of the Global Clinical Trials business unit) which provides testing services to pharmaceutical and biotechnology companies that are running clinical trials.

There are approximately 350 employees based in the UK.