This is the second in a series of articles that describe how different types of laboratory tests are developed, validated, and made available for use by patients and their health care providers. This section deals with the types of tests that are manufactured and sold in bulk to hospital and reference laboratories, clinics, doctors' offices and other health care facilities.
Commercial laboratory tests are those that are performed using commercially manufactured kits and equipment. The majority of lab tests in use today fall into this category. Unlike tests developed for use in a single laboratory or laboratory company (known as lab-developed tests), they are manufactured, marketed, and sold in volume as kits to multiple laboratories and other health care facilities. In the United States, the development and marketing of commercial tests are regulated by the US Food and Drug Administration (FDA). They are considered "medical devices" and, specifically, "in vitro diagnostic devices (IVD)." As such, they must be evaluated and approved by the FDA. Likewise, many countries around the world have agencies comparable to the FDA that are responsible for approving the use of clinical laboratory tests. Examples of commercial tests and tests systems that are often sold as kits to various laboratories include tests that detect and/or measure glucose, cholesterol, therapeutic drugs, tumor markers, and infectious diseases.
The process required for a new commercial test to gain approval for marketing by the FDA can be long and costly, sometimes taking many years before the benefits are finally realized, depending on how complicated the test is. A number of ideas for tests never make it to the clinical trial stage, where the safety and efficacy are evaluated on patient volunteers, and sometimes a promising test that doctors read about in the scientific literature never becomes commercially available. If they do become available, other federal and state health agencies ensure that these laboratory tests meet stringent standards both during the manufacturing process and when they are used in the clinical laboratory. Just because a test performs well in the research laboratory doesn't mean that it will work in the daily operations of a clinical laboratory. Commercial tests don't always make it to market or get put into practice.