What is the main use of the red top tube?

The red top tube is primarily used for collecting serum samples that do not require any additives. This type of tube is typically plain, with no anticoagulants or gel separators, which allows the blood to clot completely before centrifugation. When the blood is spun down, the cells are separated from the serum, which can then be used for various laboratory tests that require serum as the specimen.

Serum tests can include a wide variety of analyses, such as certain chemistry panels, hormone levels, and serological tests. Since there are no additives in the red top tube, it is essential for tests that need the blood to clot naturally, ensuring the integrity of the serum for accurate results.

Other choices may pertain to specific tests or preconditions for sample handling but do not align with the primary purpose of the red top tube. For example, whole blood tests typically require tubes with anticoagulants to prevent clotting, while fasting glucose tests often utilize different types of tubes that are designed specifically for glucose measurement. Coagulation studies are conducted using tubes with specific additives, such as sodium citrate, which helps to preserve the sample for accurate coagulation assessment. Thus, the red top tube's unique characteristic of containing no additives solidifies its role for serum