Laboratory Corporation of America 801 Medical Dr, Wentzville, MO63385 The Laboratory Corporation of America location in Wentzville is a full service medical laboratory that is open on…More weekdays and Saturdays. The lab offers routine clinical lab collections, specimen drop offs, occupational urine tests, standing orders, drug screens, hair testing, H. pylori breath tests to detect certain gastrointestinal ailments and lab exams for pediatrics. Paternity tests are also available. Appointments for paternity tests must be made over the phone at 1-800-742-3944. Parties may schedule appointments for all other types of tests online at Lab Corp's website.