What is the preferred specimen for glucose analysis?

What is the preferred specimen for glucose analysis?

• A. EDTA plasma
• B. Fluoride oxalate plasma
• C. Heparinized plasma
• D. Serum

Answer: (B)

The main idea is preventing glycolysis after the blood is drawn to keep the glucose level accurate. Blood cells continue to metabolize glucose in the sample, so without an inhibitor the measured level would drop over time. A gray-top tube contains fluoride, which inhibits the glycolytic enzyme enolase, and oxalate, which acts as an anticoagulant. This combination stops glycolysis and yields plasma that preserves the true glucose concentration, making fluoride-oxalate plasma the preferred specimen for glucose analysis. Serum or plasmas with other anticoagulants don’t prevent glycolysis as effectively, so they’re more likely to show falsely low glucose if there’s any delay in processing.

The main idea is preventing glycolysis after the blood is drawn to keep the glucose level accurate. Blood cells continue to metabolize glucose in the sample, so without an inhibitor the measured level would drop over time. A gray-top tube contains fluoride, which inhibits the glycolytic enzyme enolase, and oxalate, which acts as an anticoagulant. This combination stops glycolysis and yields plasma that preserves the true glucose concentration, making fluoride-oxalate plasma the preferred specimen for glucose analysis. Serum or plasmas with other anticoagulants don’t prevent glycolysis as effectively, so they’re more likely to show falsely low glucose if there’s any delay in processing.