Which tube type should be used for glucose testing when glycolysis must be prevented?

Which tube type should be used for glucose testing when glycolysis must be prevented?

• A. Gray top fluoride/oxalate
• B. Light blue citrate
• C. Red glass
• D. Lavender EDTA

Answer: (D)

Preventing glycolysis after the blood draw is essential to get an accurate glucose result. The gray-top tube provides both a glycolysis inhibitor and an anticoagulant: sodium fluoride slows glycolysis by inhibiting a key glycolytic enzyme, while potassium oxalate keeps the blood from clotting so plasma can be used for testing. Other tubes either lack a glycolysis inhibitor or contain EDTA, which does not stop glycolysis, allowing glucose levels to drop and produce falsely low readings. So the gray-top fluoride/oxalate tube is the appropriate choice for glucose testing when glycolysis must be prevented.

Preventing glycolysis after the blood draw is essential to get an accurate glucose result. The gray-top tube provides both a glycolysis inhibitor and an anticoagulant: sodium fluoride slows glycolysis by inhibiting a key glycolytic enzyme, while potassium oxalate keeps the blood from clotting so plasma can be used for testing. Other tubes either lack a glycolysis inhibitor or contain EDTA, which does not stop glycolysis, allowing glucose levels to drop and produce falsely low readings. So the gray-top fluoride/oxalate tube is the appropriate choice for glucose testing when glycolysis must be prevented.