In vitro diagnostics (IVDs) are diagnostic tests that that can detect diseases, conditions, or infections. In vitro diagnostics test a sample of tissue or bodily fluids, as opposed to testing inside the body, such as:
- Microbiological culture, which determines the presence or absence of microbes in a sample from the body, usually targeted at detecting pathogenic bacteria
- Genetic testing
- Blood glucose
- Liver function tests
- Electrolytes in the blood, such as sodium, potassium, creatinine and urea
In vitro tests can be classified according to the location of the sample being tested, including blood and urine tests.
Some tests are used health professional settings such as clinical laboratories, and other tests are for consumers to use at home. The expression in vitro comes from Latin, literally meaning “within the glass.” The name reflects the fact that historically such tests were conducted in glass vessels, such as test tubes.
Unlike other forms of medical technology, IVDs never interact directly with the human body. Their value stems from the information they provide. This sets IVDs apart from medical devices and pharmaceuticals, and is part of what makes them unique among health technologies.
In the U.S., in vitro diagnostics products are medical devices as defined in section 210(h) of the Federal Food, Drug, and Cosmetic Act, and may also be biological products subject to section 351 of the Public Health Service Act. Like other medical devices, IVDs are subject to premarket and postmarket controls. IVDs are also subject to the Clinical Laboratory Improvement Amendments (CLIA ’88) of 1988.
The IVD industry is growing steadily due to a number factors, such as increased demand for infectious disease testing as new pathogen strains develop each year, such as in seasonal influenza and H1N1, and increased incidences of hospital-acquired infections. Other factors include aging demographics common to all developed nations and the accompanying increased incidence of chronic disease across all age cohorts of the population; advances in DNA sequencing; and growing demand from emerging markets, which are only now becoming able to pay for diagnostic devices.