Can you keep clean urine in refrigerator and how long?

urine specimens should generally be processed as soon as the collection is complete. Some urine specimens ,such as urine for VMA, Cortisol, and other metabolites are collected over a 72-hour period and these specimens must be refrigerated or kept on ice during the collection process, including while the specimen is awaiting delivery to the lab. Essentially all other urine specimens are very time-sensitive, and allowing them to languish in the refrigerator instead of getting them to the lab can yield inaccurate results. The longer a specimen sits, the more chemical changes will naturally occur in the urine, and the less accurate a given test will be. This is why we usually ask you to peeatthe doctor's office instead of just sending you home with a plastic cup.