Which anticoagulant is used in the orange-lid blood collection tube for biochemistry tests?

• A. EDTA
• B. Sodium fluoride and potassium oxalate
• C. Heparinized saline
• D. Lithium heparin blood tube

Answer: (D)

The main idea is choosing an anticoagulant that lets you measure a wide range of biochemistry analytes accurately. For orange-lid tubes used in chemistry panels, lithium heparin is the additive. It prevents blood from clotting so you can obtain plasma quickly, and it generally interferes less with many chemistry assays than other anticoagulants. EDTA would bind calcium and can disrupt enzymatic reactions; a fluoride/oxalate combination is reserved mainly for glucose testing and glycolysis inhibition; and a tube with heparinized saline isn’t the standard design for routine chemistry tubes. Lithium heparin provides reliable plasma for most biochemistry tests without those common interferences.