Abstract
Biomarker assays have brought significant challenges to bioanalytical laboratories that historically have provided pharmacokinetic analytical services to the drug development industry. This has largely been due to two reasons: the lack of regulatory guidance in how to validate biomarker assays and the lack of scientists in bioanalytical laboratories with experience in this clinical arena. Since biomarkers have been measured for many decades in clinical laboratories globally, this article reviews the different types of analytical laboratories and their practices and case studies will demonstrate the potential outcomes of using biomarker assays in drug development when they are not validated correctly.