Citrate is mainly used for hemostasis testing and the determination of erythrocyte sedimentation rate. Generally, the INP value of sodium citrate with a concentration of 0.129mol/L is higher than that with a concentration of 0.109mol/L. In addition, for thromboplastin reagents from different sources, the clotting time of the plasma of the same normal person or patient can vary greatly . Therefore, the source of the thromboplastin reagent used in each laboratory should be as constant as possible, and the preparation method should be standardized, otherwise the clotting time will be prolonged or shortened, or the normal value will be irregular. Conditional laboratories can use buffered anticoagulants, which are more suitable for analysis of specimens after cryopreservation. The function of the buffer is to maintain a constant pH value of plasma and prevent the inactivation of volatile factors. 1ã??Anticoagulation mechanism Citrate is mainly sodium citrate. The principle of anticoagulation is to combine with Ca2+ in the blood to form a chelate, so that Ca2+ loses coagulation function. Calcium is an essential substance in the coagulation process and can promote the formation of thromboplastin (coagulation factor III), thrombin and fibrin. And activate the release response of platelets. Citrate ions in citrate and calcium ions in the blood form a soluble complex calcium citrate that is difficult to dissociate. This complex is easily soluble in water but not easily dissociated, reducing calcium ions in the blood and clotting. The process is inhibited, thereby preventing blood clotting. 2ã??Clinical application Sodium citrate and blood are used at a ratio of 1:9. Most coagulation tests can be used for anticoagulation with sodium citrate, which helps stabilize factor V and factor VIII, and has little effect on average platelet volume and other coagulation factors. It can be used for platelet function analysis. Sodium citrate is less cytotoxic, and it is also one of the components of blood maintenance liquid in blood transfusion. 3ã??Notes 6mg of sodium citrate can be used to anticoagulate 1ml of blood, which is strong alkaline; also because of its weak anticoagulant effect and strong alkaline, it is not suitable for blood tests and biochemical tests. Use 5 to 7% sodium citrate solution for acute blood pressure experiments. Desheng is a veteran blood testing reagent company with 15 years of R&D and production experience, and has in-depth research on blood collection tube additives.
