Blood tests provide valuable insights into a person’s health. Accurate results require precise handling of the blood sample, including using the correct collection tube. For ferritin, a protein indicating the body’s iron status, proper collection methods are essential for accurate measurement.
The Designated Tube for Ferritin
For a ferritin blood test, the most commonly designated tubes are those designed to collect serum: gold-top or red-top tubes. Gold-top tubes, also known as serum separator tubes (SSTs), contain a gel and a clot activator. Red-top tubes are plain serum tubes, often containing a clot activator. Some laboratories may also accept green-top tubes, which contain lithium heparin to yield plasma, or lavender-top tubes containing EDTA, though serum is generally preferred for ferritin analysis.
The Role of the Tube’s Additive
The specific additives within these tubes play a crucial role in preparing the blood sample for accurate ferritin measurement. For gold-top (SST) and red-top tubes, the clot activator accelerates the clotting process.
Once the blood clots, the serum separator gel in SSTs forms a stable barrier between the clotted blood cells and the liquid serum during centrifugation. This physical separation prevents interaction between the serum and cellular components, which could otherwise affect the ferritin concentration over time.
For green-top tubes, lithium heparin acts as an anticoagulant, preventing the blood from clotting. This allows for the collection of plasma. The goal of the additive is to ensure the ferritin protein remains stable and its concentration accurately reflects the body’s levels, preventing sample degradation and interference.
Understanding Ferritin Levels
Ferritin is a protein found within cells that serves as the body’s primary iron storage unit. It sequesters iron in a soluble and non-toxic form, acting as a buffer against both iron deficiency and iron overload. When the body needs iron, ferritin releases it for various functions, including hemoglobin production for oxygen transport.
Measuring ferritin levels provides a direct indication of the amount of iron stored in the body. Healthcare providers commonly order this test to assess iron stores, diagnose iron deficiency anemia, or identify conditions of iron overload such as hemochromatosis.
Ferritin levels can also be elevated in the presence of inflammation, chronic infections, liver diseases, or certain cancers, as it functions as an acute-phase reactant. Understanding these levels helps in managing iron-related disorders and monitoring overall health.