Final answer:
If a urine specimen is not delivered to the lab within 30 minutes, it must be refrigerated or kept on ice to preserve the testing components. This is particularly important for tests with time-sensitive reactions and for maintaining the integrity of the specimen over a longer collection period, such as a 24-hour urine collection.
Step-by-step explanation:
Proper Storage and Handling of Urine Specimens
When a urine specimen cannot be delivered to the laboratory within 30 minutes of collection, it requires special handling to ensure that the components being tested are not altered. In such cases, the urine must be refrigerated or kept on ice, which slows down the metabolic processes of any bacteria present and preserves the integrity of the sample.
In certain tests, like those for urinary glucose levels, the timing of the analysis is crucial due to the test reactions' rates being affected by catalysis via special enzymes embedded in the test strip pads.
For a 24-hour urine collection, which may be used to measure various substances like magnesium, sodium, uric acid, and phosphate, keeping the sample at a consistent temperature and avoiding contamination are important factors.
Moreover, for the accuracy of test results, it is critical not to introduce any external substances into the urine, such as blood, which can occur due to menstrual contamination. Understanding how to appropriately store and transport urine helps maintain the integrity of the specimen for reliable medical examination.