US Clinical Laboratory Improvement Amendments (CLIA) Regulations (42 CFR Part 493) 1253: Before reporting patient results on an unmodified FDA-cleared or approved test system, verify accuracy, precision and reportable range and confirm the manufacturer's reference intervals suit the patient population; for a modified, in-house or non-FDA test system, establish accuracy, precision, analytical sensitivity and specificity including interferences, reportable range, reference intervals and any other needed characteristic; set calibration and control procedures from those specifications; and document everything

What does 1253 require?

Each laboratory that introduces an unmodified FDA-cleared or approved test system must, before reporting patient results, demonstrate that it can obtain performance specifications comparable to the manufacturer's for accuracy, precision and reportable range, and verify that the manufacturer's reference intervals are appropriate for its patient population. Each laboratory that modifies an FDA-cleared or approved test system, introduces a test system not subject to FDA clearance or approval (including methods developed in-house and standardised textbook methods), or uses a test system whose performance specifications the manufacturer does not provide must, before reporting patient results, establish for each test system its accuracy, precision, analytical sensitivity, analytical specificity including interfering substances, reportable range, reference intervals and any other performance characteristic required for test performance. The laboratory must then determine the test system's calibration and control procedures from the specifications verified or established, and must document all of these activities. Systems in use before April 24, 2003 are exempt from this section.