According to best laboratory practices, how many controls are needed during validation?

During the validation of laboratory tests, having two controls – a negative control and a positive control – is considered standard best practice. This approach ensures that the test system is functioning correctly.

The negative control confirms that there are no false positives, meaning that when the test is conducted on a sample that should not show a result (such as a sample without the substance being tested for), it returns an expected negative outcome. This helps to identify any contamination or issues with the reagents or procedures.

The positive control, on the other hand, verifies that the test is capable of detecting the targeted analyte or pathogen. This control is critical for demonstrating that the assay performs adequately under expected conditions, providing confidence that a positive result with an actual sample is accurate.

Having these two controls in place is essential for establishing both the specificity and sensitivity of a test, thereby ensuring that the results obtained are reliable and trustworthy. While it is possible to use more than two controls for further verification, the standard practice is to utilize at least one of each type to validate performance effectively.