Generally, urine is the most useful specimen to test for the presence of a wide variety of drugs, drug metabolites and toxins. Although serum can be used for testing and determining the quantitation of drug levels, it is not a substitute for urine screening which detects the presence of substances for days rather than just hours.
Gastric specimens (stomach contents) are also clinically useful. However, a gastric specimen analysis may be unnecessary when drug absorption is complete.
Information on the specific specimen collection, transport, stability and rejection criteria for each PeaceHealth Laboratories test can be found by looking up the test in the test menu search on the left sidebar of our Web site.
For employment-forensic drug testing, PeaceHealth Laboratories maintains specimen and specimen aliquot chain of custody procedures and documentation. Our workplace drug test results are certified prior to reporting. Any specimen that is not negative is secured and kept frozen under chain of custody for at least one year.
Chain of custody procedures are not used in clinical toxicology drug testing intended for diagnostic and medical treatment purposes; clinical tests should not be used for legal forensic purposes.