Which specimen requires chilling immediately after collection to prevent degradation?

Which specimen requires chilling immediately after collection to prevent degradation?

• A. Hemoglobin A1c
• B. Ammonia
• C. Potassium
• D. Sodium

Answer: (B)

Ammonia in blood is highly unstable once drawn; leukocytes and bacteria keep metabolizing and producing ammonia after collection, which can raise the measured level if the sample isn’t kept cold. To prevent that in vitro production, the specimen is collected in a pre-chilled tube and kept on ice immediately, with rapid transport to the lab and prompt processing. This chilly handling slows enzymatic activity and preserves the true ammonia concentration. Hemoglobin A1c, potassium, and sodium do not require this immediate chilling because their levels remain stable under typical handling conditions when proper collection and handling guidelines are followed.

Ammonia in blood is highly unstable once drawn; leukocytes and bacteria keep metabolizing and producing ammonia after collection, which can raise the measured level if the sample isn’t kept cold. To prevent that in vitro production, the specimen is collected in a pre-chilled tube and kept on ice immediately, with rapid transport to the lab and prompt processing. This chilly handling slows enzymatic activity and preserves the true ammonia concentration.

Hemoglobin A1c, potassium, and sodium do not require this immediate chilling because their levels remain stable under typical handling conditions when proper collection and handling guidelines are followed.