What anticoagulant is found in the green top tube?

The correct answer is that the green top tube contains heparin, an anticoagulant that works by inhibiting thrombin and factor Xa in the coagulation cascade. This allows for blood samples to be collected for various tests without allowing the blood to clot. Heparin is particularly useful for tests that require plasma, such as chemistry analyses, because it prevents clotting while still allowing for accurate measurement of substances in the plasma.

Understanding the role of heparin is important in clinical settings where timely and accurate results are critical. The preference for heparin in green top tubes over other anticoagulants is partly due to its rapid action and the fact that it does not interfere with many laboratory tests, making it a versatile choice for different types of analyses.