Program Information Quest Diagnostics is the leading provider of esoteric testing, including gene-based testing and is the leader in routine medical testing, drugs of abuse testing, and non-hospital based anatomic pathology testing. Quest Diagnostics, together with its MedPlus subsidiary, empowers healthcare organizations and clinicians with state-of-the-art connectivity solutions that improve practice management. Through partnerships with pharmaceutical, biotechnology and information technology companies, Quest Diagnostics provides support to help speed the development of healthcare insights and new therapies.