What is a common use for a green top tube?

A green top tube is commonly used for biochemical tests because it contains heparin as an anticoagulant. Heparin prevents the blood sample from clotting, allowing for the analysis of plasma and various biochemical components present in the blood. This is particularly relevant in assessing organ function, electrolytes, and metabolic status.

In contrast, serum separation requires a different type of tube, typically a red top or a gold top tube, which are designed to allow the blood to clot and then separate the serum from the cells during centrifugation. Coagulation tests usually utilize a blue top tube, which contains sodium citrate and is specifically designed to measure clotting factors. A complete blood count is often performed using a lavender or purple top tube that contains EDTA as an anticoagulant, which is ideal for preserving cellular components in the blood for evaluation. Thus, the green top tube's role in biochemical tests is well-defined and distinct from the purposes of the other tube types mentioned.