A gold top blood test, also known as a serum separator tube (SST) or sometimes a yellow top tube, is a common blood collection tube used for a wide variety of laboratory tests. It's primarily used to collect serum, which is the liquid portion of blood that remains after clotting.
What Makes it Different?
The key feature of a gold top tube is the presence of a gel separator at the bottom of the tube. This gel acts as a barrier between the serum and the blood cells after centrifugation (spinning the blood sample at high speed). This separation process allows for the easy collection of serum, which is then used for various tests.
Common Uses
Gold top tubes are the preferred choice for many tests because serum is needed for many common clinical chemistry and serology analyses. This includes a vast majority of Biochemistry, Immunology, and Serology tests.
- Biochemistry: Tests measuring substances in the blood such as glucose, cholesterol, liver function tests, kidney function tests, etc.
- Immunology: Tests that analyze the body's immune system, including antibody levels.
- Serology: Tests that detect antibodies or antigens in the blood, often used in diagnosing infectious diseases.
Procedure
Once blood is collected in a gold top tube, it's important to gently invert the tube six times to ensure proper mixing of the blood and the clot activator within the tube. This activates the clotting process. After the blood clots, the sample is centrifuged. The gel separator then creates a physical barrier separating the serum from the blood cells and the clot. This allows for clean serum collection and accurate test results.
Importance of Correct Tube Selection
Choosing the correct blood collection tube is critical for accurate test results. Using the wrong tube type can lead to inaccurate or unusable results. For instance, using a tube that doesn't separate serum would contaminate the serum sample with blood cells, affecting test results.