Final answer:
Marbled red/gray tubes contain a serum separator gel and clot activator, which allows for the separation of serum from cellular components after blood clotting and centrifugation. Serum lacks coagulation factors, and these tubes facilitate the processing of blood samples for various tests.
Step-by-step explanation:
Marbled red/gray tubes, often referred to as tiger top or serum separator tubes, contain C) Serum separator gel and clot activator. These components facilitate blood sample processing by causing blood to clot and separate the serum from the cells. The serum contains water, proteins including antibodies, electrolytes, antigens, hormones, and excretory products, but importantly, it does not contain the coagulation factors present in plasma. The clot activator promotes rapid blood clotting, and the serum separator gel ensures that the clear serum remains separated from the cellular components once the blood sample is centrifuged.
Blood plasma is the liquid portion of the blood that contains various substances needed for the body's functions along with the coagulation factors. In contrast, serum, which is the fluid that remains after removing clotting factors from plasma, does not contain these factors. Platelets, red blood cells, and fibrinogen are among the major components relevant to clotting and serum separation.