The donor specimen sat out all weekend unrefrigerated, is it still okay for testing?
Yes, however Forensic Laboratories recommends testing an unrefrigerated specimen within fourteen days of collection. It is known that the concentrations of some drugs and their metabolites decrease gradually in room temperature urine. Refrigeration can slow this process and freezing will preserve a sample indefinitely. Usually the decrease is minmal, but in the worst-case scenario, a borderline positive level might drop below the detection threshold. An unrefrigerated specimen should never cause a false positive, with one important exception. Alcohol may form in unrefrigerated urine due to fermentation, if the urine sugar (glucose) is elevated, such as in diabetes. We recommend that alcohol screens be shipped promptly, and we check for the presence of glucose in all positives. How do I know if a sample has been tampered with or mixed up with another sample after collection? All samples are carefully labeled at the collection site and contain a tamper-evident seal that is placed over th
