How soon should a urine specimen be delivered to the laboratory after collection?

The ideal timeframe for delivering a urine specimen to the laboratory is within 2 hours of collection. This is important because urine can undergo several changes if not analyzed promptly. Factors such as temperature, pH, and the presence of bacteria can alter the composition and integrity of the urine sample, potentially leading to inaccurate test results.

If the specimen remains at room temperature for longer than 2 hours, various biochemical processes can occur, including bacterial proliferation, which can result in increased turbidity and changes in chemical constituents like glucose and ketones. Additionally, prolonged storage can lead to the breakdown of cells and changes in sediment components, affecting microscopic examination results.

While some guidelines may allow for slightly longer times under specific conditions (such as refrigeration), the standard recommendation is to ensure the sample is processed or preserved (i.e., refrigerated) within the 2-hour window to maintain its reliability and accuracy for diagnostic purposes. This timeframe is critical for obtaining the most accurate results from the urinalysis.