The term you're looking for in FDA speak is 'Laboratory Designed Test', I've included a link to the FDA's guidance document on LDTs below. The reason why FDA a

The term you're looking for in FDA speak is 'Laboratory Designed Test', I've included a link to the FDA's guidance document on LDTs below. The reason why FDA approved tests frequently work as 'black boxes' is because the FDA requires that approved tests reach specific performance characteristics. Typically in order to prove these performance characteristics, companies must constrain the parameters of the testing. Once they do that that test is only considered 'valid' over those parameters. The level of error reporting is dependent on the company who develops the test. The FDA is working to subjecting certain LDTs (basically stuff that guides treatment choices) to pre-market review, so a lot of these gaps will likely begin to be closed. One of the things that Theranos kinda trumpeted earlier is that their nanotainer HPV test was technically a LDT and therefore did not require a 510k, but they got it anyways. http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/InVitroDiagnostics/ucm407296.htm http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedur...