The CACL adheres to a strict Quality Assurance Program. Each analytical procedure has Standard Operation of Procedure (SOP) for certification, linearity determination, proficiency testing and calibration. The laboratory uses the National Institute of Standard and Technology (NIST) reference and commercial materials for verification. The NEL participates in the College of American Pathologists (CAP) Inter-laboratory Comparison & Survey Program and the American Proficiency Institute (API) Testing Program for all licensed procedures. Other Inter-laboratory Round Robin and Quality Assurance Programs include NIST Micronutrients Measurement Quality Assurance Program, Northwest Lipid Research Center Proficiency &Quality Assurance Program, State of New York Department of Health Proficiency Testing Program, DEQAS Vitamin D External Quality Assessment Scheme and the NIST/NIH Vitamin D Metabolites Quality Assurance Program (VitDQAP). The laboratory uses David Rhodes Associates, Inc., EP Evaluator Program for statistical evaluation.