Grey Blood Vacuum Collection Tube
Short Description:
Potassium oxalate/sodium fluoride gray cap. Sodium fluoride is a weak anticoagulant. It is usually used in combination with potassium oxalate or sodium ethiodate. The ratio is 1 part of sodium fluoride and 3 parts of potassium oxalate. 4mg of this mixture can make 1ml of blood not coagulate and inhibit glycolysis within 23 days. It is a good preservative for blood glucose determination, and cannot be used for the determination of urea by urease method, nor for the determination of alkaline phosphatase and amylase. Recommended for blood sugar testing.
Objectives: Glucose is one of the most frequently measured analytes in laboratories. Most recent studies on glucose stabilities confirm that the sodium fluoride/potassium oxalate (NaF/KOx) tube is far from the gold standard. Citrate tubes have been suggested as the preferred tube type by many institutions. Greiner has introduced a glucose-specific tube (Glucomedics) containing NaF/KOx, citrate, and EDTA to minimise glycolysis. The aim was to determine which tube would be the most suitable for accurate glucose estimation in a routine laboratory setting.
Design and methods: The study process involved three experiments: (a) participant comparison using lithium heparin plasma as the comparative sample; (b) stability study (0, 1, 2 and 4 h); and (c) minimal fill volume for the citrate and the Glucomedics tubes.
Results: The patient comparison study of lithium heparin plasma showed that EDTA, NaF/KOx, and both citrate and Glucomedics if corrected for dilutional factors produced acceptable results. The stability study up to 4 h showed that the Glucomedics tube was most effective in preventing clinically significant change in glucose concentration at a room temperature. Both citrate and Glucomedics need to be filled within 0.5 mL of the recommended fill volume for acceptable results.
Conclusion: The Glucomedics tube is the most suitable for minimising glycolysis. Further improvements to it (use of correct dilutional factor and the addition of gel separator) would make this tube the benchmark for the most accurate estimation, best diagnosis and patient care decisions.
