When should urine specimens be refrigerated?

• A. If not tested within 1 hour
• B. Always refrigerate
• C. Never refrigerate
• D. Refrigerate after 24 hours

Answer: (A)

The main idea is to keep urine specimens stable so test results reflect the original sample rather than changes that happen after collection. If testing can’t be done within about an hour, refrigerating the sample slows bacterial growth and minimizes chemical changes that could alter measurements, making the results more reliable. This is why the best choice is to refrigerate when there will be a delay. It’s not necessary to refrigerate every time, because some tests or workflows may be performed at room temperature, and waiting beyond 24 hours is generally too long even with refrigeration. When you do refrigerate, keep the sample cold (2–8°C), and before testing bring it to room temperature and mix well to re-suspend any solids or crystals.