What color tube is used for serum tests?

The red top tube is specifically designed for serum tests because it does not contain any additives that would interfere with the biochemical analysis of the serum. When blood is drawn into a red top tube, it is allowed to clot, and after centrifugation, serum can be separated from the blood cells. This is crucial for serum tests, which rely on analyzing the liquid portion of the blood after clotting has occurred.

In contrast, while the green top tube contains heparin and is used for plasma tests, the light blue tube contains sodium citrate, which is primarily used for coagulation tests. The lavender top tube contains EDTA as an anticoagulant and is typically utilized for complete blood counts and other hematology tests, which require whole blood rather than serum. Thus, the characteristics and intended use of the red top tube make it the correct choice for serum tests.