Which type of sample should not be refrigerated before transport?

Whole blood should not be refrigerated before transport because cooling can cause cellular components to undergo changes that may affect the test results. Refrigeration of whole blood can lead to a decrease in cellular metabolism but can also compromise cellular integrity, particularly for tests that assess membrane stability or enzyme activity. For example, red blood cells may lyse in a cold environment, leading to inaccurate results in hemolysis tests.

In contrast, serum and plasma are often stable under refrigeration, as they do not have the same cellular components that can be adversely affected by cooling. Frozen tissue is typically preserved in a frozen state and is specifically designed for storage at very low temperatures to maintain the integrity of the cells and their structures for later analysis. Thus, whole blood remains the sample type that should be handled with care when it comes to temperature control before transport.