Description :
Testing of biological samples has become a key component in identifying and addressing drug misuse. Urine remains the primary sample for drug testing, but other samples such as oral fluid, sweat, and hair have also been used. Every testing program is different, but there are common components throughout the programs. A single test is not used to identify a positive sample; Positive results are only reported after a positive initial test and a positive confirmation test. Focus cutoffs are used to distinguish between negative and positive samples. Proficiency testing programs and laboratory accreditation are also components of the forensic examination process.