SIDEBAR 1
Laboratory-developed Tests There is a group of tests that does not require FDA-approval, called laboratory-developed assays. Unlike commercial kits, which are purchased by the lab ready-to-use, these tests are developed in the laboratory and undergo in-house validation to ensure their reliability.
Examples include microscopic examinations (such as
Pap smears and manual cell counts),
erythrocyte sedimentation rates (ESR or sed rates), microbiology
cultures and sensitivities, examination of tissue sections (including staining protocols), and blood cross-matching procedures. Many of these tests are for processes to detect mutations in
genes, such as the
BRCA genes for
breast cancer.
There are several reasons why a lab may choose to use a lab-developed test. For example, a kit may not exist for a genetic test for a disease that only a small subset of the population has – the incentive for a manufacturer to develop that test would be low because of such a small market for the product. Or, an existing test may not apply to a particular subpopulation from which the lab has patients, so adjustment of the test is required.
Although these tests are not FDA-approved, some of the reagents, controls, and equipment used in these tests may be manufactured (and are FDA-approved). In addition, methods of quality assurance are carefully followed by the laboratories that perform these types of complex tests and are highly regulated under the federal government’s Clinical Laboratory Improvement Amendments (CLIA) (see our
article on Lab Oversight).
