What additive works to maintain glucose stability as well as prevent glycolysis?

Sodium fluoride is the correct additive for maintaining glucose stability and preventing glycolysis in blood samples. Glycolysis is a metabolic process where glucose is broken down, and this can occur in the blood sample after collection, potentially leading to inaccurate test results.

Sodium fluoride acts as a glycolytic inhibitor, effectively stopping the action of enzymes that facilitate glycolysis. This allows for accurate measurement of glucose levels in laboratory tests since it preserves the glucose concentration in the sample.

In contrast, the other additives listed do not provide the same effects regarding glucose stabilization. EDTA is primarily used as an anticoagulant for hematological tests, sodium heparin also serves as an anticoagulant but does not inhibit glycolysis, and potassium oxalate can act to prevent clotting but is less effective at preserving glucose levels compared to sodium fluoride. Thus, for tests requiring stable glucose measurements, sodium fluoride is essential.