How should a urine specimen be stored if not analyzed immediately?

When a urine specimen cannot be analyzed immediately, the appropriate method of storage is refrigeration. Keeping the specimen refrigerated slows down bacterial growth and reduces the degradation of analytes that could occur at higher temperatures. This is crucial for maintaining the integrity of the sample and ensuring accurate results when it is eventually tested.

Room temperature storage can lead to the proliferation of bacteria and changes in chemical composition, which can significantly alter the results of tests such as pH, specific gravity, and the presence of certain substances. Freezing urine is not typically recommended unless specifically indicated, as it can cause cellular lysis and release of constituents that may affect test results. Storing the specimen in a dark cabinet does not adequately control temperature and does not prevent the changes that could compromise the sample's integrity. Thus, refrigeration stands out as the best practice for preserving the quality of urine specimens prior to analysis.