What must be done to urine specimens before testing?

To ensure accurate test results, urine specimens must be stored properly before testing. Refrigerating urine specimens slows down the growth of bacteria and helps prevent changes in the composition of the sample, which can occur if the specimen is left at room temperature for an extended period. This preservation process is essential for maintaining the integrity of the sample, allowing for reliable analysis when testing for various substances, including drugs, proteins, and glucose.

Other methods of specimen handling, such as freezing or heating in a microwave, are not standard practices for preserving urine samples prior to testing. Using preservatives can be appropriate in specific situations but is not universally required for all types of urine tests. Therefore, proper refrigeration is the most accepted and critical step to ensure the accuracy of urine test results.