Which lab tube additive is commonly used for glucose testing?

Sodium fluoride is commonly used as an additive in lab tubes designated for glucose testing because it serves as a glycolytic inhibitor. This means that it prevents the breakdown of glucose by inhibiting the enzymes that facilitate glycolysis. When blood is collected for glucose testing, it is essential to preserve the glucose present in the sample until testing can occur. Sodium fluoride effectively stabilizes glucose levels in the sample, ensuring accurate test results.

In contrast, EDTA is an anticoagulant that is primarily used in hematology for complete blood counts and is not suitable for glucose testing, as it does not prevent glycolysis. Heparin is another type of anticoagulant that helps to prevent blood clotting but may not adequately preserve glucose levels. Sodium citrate is mainly used for coagulation studies and can also interfere with glucose measurement, making it an inappropriate choice for glucose testing. Thus, sodium fluoride is the preferred additive for maintaining accurate glucose levels in lab specimens.