What is the additive found in gray collection tubes?

The additive found in gray collection tubes is indeed Sodium Fluoride and Potassium Oxalate. These additives serve specific purposes in the blood collection process. Sodium Fluoride acts as a glycolytic inhibitor, which means it prevents the breakdown of glucose in the blood sample. This is particularly important when testing for glucose levels, as any breakdown would lead to inaccurate results. Potassium Oxalate, on the other hand, acts as an anticoagulant that prevents blood from clotting by binding calcium ions, further ensuring that the sample remains in a liquid state and is representative of the actual blood composition at the time of collection.

This combination is particularly useful for specific tests, such as those evaluating blood glucose levels, as it preserves the integrity of the analytes of interest during storage and transport. The other options listed pertain to different types of additives found in other tubes used for various laboratory tests, each having their own unique roles, but they do not apply to gray collection tubes.