At what temperature should a PT sample be stored until collected by a courier?

For a prothrombin time (PT) sample, the correct storage recommendation is at room temperature until it is collected by a courier. PT tests require the sample to maintain its stability, and room temperature ensures that any coagulation factors remain in an optimal state. Storing the sample at room temperature prevents degradation or changes in the sample that could occur if it is either refrigerated or frozen, which can affect the test results.

When PT samples are stored at temperatures above freezing and not subjected to refrigeration, this helps to preserve the integrity of the coagulation factors necessary for accurate testing results. Many laboratory guidelines specify that samples may be kept at room temperature (typically defined as around 20-25°C or 68-77°F) for a limited period before testing.

In contrast to other storage options like refrigeration, which can lead to the deterioration of certain components, or freezing, which can cause hemolysis or alter the constituents of the sample, room temperature is optimal for ensuring the stability and reliability of the test result in this scenario.