A sample sat out all weekend unrefrigerated, is it still acceptable for testing?
Yes. However we advise testing an unrefrigerated sample as soon as possible and not to exceed 5 days after collection. Concentrations of certain drugs and their metabolites decrease gradually in room temperature urine. Refrigeration can slow this process and freezing the sample can preserve it indefinately. An unrefirgerated sample would never cause a false-positive with one important exception; alcohol may form in unrefrigerated urine due to fermentaion, if the urine sugar (glucose) is elevated, such as in the case of diabetes. We recommend, if possible, refrigerating your samples and shipping all samples as soon as possible.
