Final answer:
Sodium Fluoride is the antiglycolytic agent used to maintain glucose stability in blood samples for up to 3 days, preventing glycolysis and ensuring accurate glucose measurements.
Step-by-step explanation:
The antiglycolytic agent known for maintaining glucose stability for up to 3 days is Sodium Fluoride. When blood samples are collected for glucose testing, it's crucial to prevent the glucose from being metabolized, which would lead to falsely low glucose levels. Sodium Fluoride inhibits glycolysis, the pathway by which glucose is metabolized, thus ensuring the glucose stability needed for accurate measurement.