With our ever-increasing understanding of the molecular basis of disease, clinical laboratories are implementing a variety of molecular diagnostic tests to aid in the diagnosis of hereditary disorders, detection and monitoring of cancer, determination of prognosis and guidance for cancer therapy, and detection and monitoring of infectious diseases. Before introducing any new test into the clinical laboratory, the performance characteristics of the assay must be "verified," if it is a US Food and Drug Administration (FDA)-approved or FDA-cleared test, or "validated," if it is a laboratory-developed test. Although guidelines exist for how validation and verification studies may be addressed for molecular assays, the specific details of the approach used by individual laboratories is rarely published. Many laboratories, especially those introducing new types of molecular assays, would welcome additional guidance, especially in the form of specific examples, on the process of preparing a new molecular assay for clinical use.