Exposure time of plasma or serum to cells can affect test results.

Exposure time of plasma or serum to cells can affect test results.

• A. True
• B. False
• C. Not enough information
• D. It depends

Answer: (A)

Exposure time matters because cells in a blood sample stay active after collection. When plasma or serum sits in contact with those cells, ongoing cellular processes can change the composition of the specimen and shift test results. For example, residual cells continue glycolysis, which can lower glucose levels; cells may release potassium or other substances if they lyse or stay in contact for too long; enzymes and other analytes can drift as well. Because of this, promptly separating plasma or serum from cells and properly handling and storing the sample helps maintain true values. This is why the statement is true.

Exposure time matters because cells in a blood sample stay active after collection. When plasma or serum sits in contact with those cells, ongoing cellular processes can change the composition of the specimen and shift test results. For example, residual cells continue glycolysis, which can lower glucose levels; cells may release potassium or other substances if they lyse or stay in contact for too long; enzymes and other analytes can drift as well. Because of this, promptly separating plasma or serum from cells and properly handling and storing the sample helps maintain true values. This is why the statement is true.