How does refrigeration affect a urine sample?

Refrigeration is essential for urine sample collection and storage prior to analysis. By cooling the sample, it helps preserve the integrity of various constituents within the urine for several hours, typically in the range of 6 to 12 hours. This preservation is crucial because it slows down metabolic processes and bacterial growth, thereby reducing the chances of alterations in sample composition that could lead to inaccurate test results.

While refrigeration does significantly slow bacterial growth, it does not completely halt it, which is why it's important to process the urine sample as soon as possible. Additionally, refrigeration does not increase glucose levels; rather, it helps to maintain the concentrations of various solutes, including glucose, until analysis can be conducted. Thus, while refrigeration aids in preserving a sample's integrity, the degree of effectiveness and the specific time window for which it is suitable must be considered.