Which additive is used in the gold top tube?

The gold top tube contains a clot activator and gel, making this the correct choice. The clot activator facilitates the clotting process by providing a surface that promotes platelet activation and aggregation. The gel, which forms a barrier between the serum and the cellular components once the sample is centrifuged, helps to separate serum from thrombus for further analysis. This tube is commonly used for serological tests and various chemistry panels, as the serum produced contains valuable information for diagnostic purposes.

Understanding the purpose of each additive in different tubes is crucial for proper specimen handling and achieving accurate laboratory results. In contrast, the other additives, such as EDTA, heparin, and sodium citrate, serve specific roles for different types of tests—they act as anticoagulants and prevent clot formation, which is not suitable for the tests typically performed on samples collected in a gold top tube.