Which analyte is reported to increase when samples are stored at 4°C?

Which analyte is reported to increase when samples are stored at 4°C?

• A. ALP
• B. Glucose
• C. Creatinine
• D. Urea

Answer: (A)

Temperature can affect how quickly analytes change in stored samples. Some enzymes can leak from cells into serum during storage, and refrigeration can allow this leakage to continue at a slow but detectable rate. Alkaline phosphatase is one such enzyme, so when a sample is kept at 4°C, its activity can rise as enzymes are released from cells or membranes over time, leading to an increased measurement. In contrast, glucose tends to fall during storage due to ongoing glycolysis, even at 4°C; creatinine and urea are generally more stable and do not typically show increases with refrigerated storage. Therefore, the analyte that increases with 4°C storage is alkaline phosphatase.

Temperature can affect how quickly analytes change in stored samples. Some enzymes can leak from cells into serum during storage, and refrigeration can allow this leakage to continue at a slow but detectable rate. Alkaline phosphatase is one such enzyme, so when a sample is kept at 4°C, its activity can rise as enzymes are released from cells or membranes over time, leading to an increased measurement.

In contrast, glucose tends to fall during storage due to ongoing glycolysis, even at 4°C; creatinine and urea are generally more stable and do not typically show increases with refrigerated storage. Therefore, the analyte that increases with 4°C storage is alkaline phosphatase.