To arrive at the most appropriate decision regarding patient management, an essential step for medical practitioners is to determine a correct and accurate diagnosis of the patient's condition. In recent years there have been significant technological efforts in chemistry, biochemistry, laboratory science, and biotechnology toward improving disease diagnosis and management in patients. Further, drug developers have utilized some of these novel diagnostic methods during preclinical and clinical trials that have led to creating efficiencies in their development processes. This book provides an overview of diagnostic procedures that aid in precision medicine and the drug development process.