SODIUM CITRATE, 3.8% w/v

Sodium Citrate 3.8% is used as an anticoagulant to prevent blood clotting in laboratory coagulation testing. It works through its mild calcium-chelating properties that lower the free calcium levels required for the coagulation cascade.
Citrated blood is especially appropriate for coagulation studies such as Prothrombin Time (PT) and activated Partial Thromboplastin Time (aPTT). Sodium citrate is commonly preferred for these tests because coagulation factor V remains relatively stable in properly collected citrated blood samples. The controlled anticoagulant action allows coagulation studies to be performed after laboratory processing.
The solution contains 3.8% sodium citrate and has a clear, colourless appearance. The specified pH of a 2% solution at 25°C is 6.5-7.0. Proper blood-to-anticoagulant proportion is important for obtaining reliable coagulation results.
Higher citrate concentration may influence clotting measurements under certain conditions. Use of 3.8% sodium citrate can produce falsely prolonged clotting times, particularly with slightly underfilled tubes or samples from patients with high hematocrit values. Careful specimen collection and appropriate filling of collection tubes are therefore essential for accurate results.
The solution should be handled according to established laboratory procedures and applicable coagulation testing guidelines.

Supports blood sample anticoagulation by binding calcium and preventing clot formation during coagulation testing.