Which tube is used for collecting peripheral blood when sodium heparin is required?

The green top tube is the correct choice for collecting peripheral blood when sodium heparin is required because it contains lithium heparin, an anticoagulant that is effective for preventing blood coagulation. Sodium heparin works by inhibiting thrombin and factor Xa, facilitating the study of blood components without the interference of clotting.

The use of the green top tube is especially crucial in certain tests that require plasma rather than serum. This tube is commonly utilized for various biochemical tests and can be beneficial for rapid processing because it allows for quick separation of plasma from blood cells.

Other tube types have different additives that serve various purposes. The blue top tube typically contains sodium citrate, which is used for coagulation studies, while the red top tube usually contains no additive or a clot activator and is generally used for serum collection. The yellow top tube often contains a medium or additive that supports culture growth, not suitable for heparinized plasma collections. Each of these tubes has a specific role, emphasizing the importance of selecting the appropriate collection tube based on the required test parameters.