Heparin Sodium: An acidic anticoagulant natural anticoagulant containing a sulfate group. Heparin is a collective name for a cluster of acidic mucopolysaccharide mixtures of various molecular weights, with linear chain molecules consisting of repeating units of hexasaccharide or octasaccharide, having a molecular weight of between 3,000 and 30,000 Da and an average molecular weight of about 15,000 Da.

Heparin is widely found in mammalian liver, lung, and intestinal mucosa, and binds to proteins as complexes. Enzymolysis protein can be separated heparin, heparin is a mucopolysaccharide containing sulfuric acid, amino, aldonic acid. At pH 8-9, it is negatively charged and can be ion-exchanged with anion exchangers for crude separation. The polysaccharide solution is precipitated in highly concentrated ethanol and purified.

Heparin in the tissue and other mucopolysaccharides together with the protein into a complex, so the heparin preparation process, including heparin protein complex extraction, dissociation and heparin separation and purification of two steps.

Heparin molecules contain sulfate and carboxyl groups, was strongly acidic, as a polyanion, can react with the cation into a salt. These cations include metal cations: Ca2 +, Na +, K +, long-chain pyridine compounds of organic bases such as cetylpyridinium chloride (CPC), strychnine, basic dye Azure A, cationic surfactants Long chain quaternary ammonium salts) such as cetyltrimethylammonium bromide; cation exchangers and positively charged proteins such as fishmeal 0 protein and the like.

N-sulfate in heparin structure and anticoagulant effects are closely related, such as being destroyed, the anticoagulant activity is reduced. N-sulfate is sensitive to acid hydrolysis and is fairly stable under alkaline conditions. Free hydroxyl in heparin molecule is esterified, such as sulfation, anticoagulant activity also decreased, acetylation does not affect its anticoagulant activity.

Heparin is white or almost white powder, odorless and tasteless, hygroscopic, easily soluble in water, insoluble in ethanol, acetone, dioxane and other organic solvents.

Alkaline deficiency caused by acid extraction, then in the case of high temperature, rapid destruction of heparin, warming too early will make the protein early solidification, affecting heparin decomposition and dissolution. The use of proteolytic enzymes specifically hydrolyzed protein characteristics, combined with the acid and the removal of protein protein removal method, the use of enzymatic deproteinization method, the method can remove the protein less affect the total titer of heparin. In the transfer of acid in the process of removing protein, in order to prevent the inactivation of heparin, adding sodium bisulfite as a protective agent. Centrifuge the proteins at low temperature.

Heparin is the best anticoagulant in blood chemistry. Heparin is a sulphate-containing mucopolysaccharide with a molecular weight of 15,000. Its anticoagulant mechanism, together with antithrombin II, inhibits the action of factor Ⅸa, Ⅷ and PF3 at low concentrations and enhances anticoagulation Thrombin III inactivates serine proteases, thus preventing the formation of thrombin; as well as inhibiting the self-catalysis of thrombin and the action of inhibiting factor X. Heparin salts are sodium, lithium, ammonium salt. The usual anticoagulant dose with heparin is 10.0 to 12.5 IU / mL of blood. Common clinical heparin lithium, although its price is more expensive, but better anticoagulant effect. Because heparin can increase the plasma sodium content, and heparin ammonium can increase the content of urea ammonia. Some biochemical components in serum and heparin plasma anticoagulation significant difference. In the process of clotting, the content of serum potassium is higher than that of plasma due to the dissolution and destruction of erythrocytes. Since the plasma contains Fg, its content is higher than that of serum. Therefore, the determination of potassium ions, pay attention to the difference between serum and plasma. In addition, excessive heparin can cause leukocyte aggregation and thrombocytopenia, it is not suitable for white blood cell classification and platelet count, but can not be used for hemostasis test. The experiment shows that adding heparin anticoagulant after blood sampling has obvious effect on measuring the total protein content in the blood, which will make the measured result be higher than 3% ~ 5% of the total protein measured by the serum. However, the addition of anticoagulants, the total protein content less than the total serum protein content, the reason is that the addition of heparin sodium blood anticoagulant, blocking the formation of thromboplastin, preventing blood coagulation, resulting in fibrinogen can not The hydrolysis converts to fibrin monomers, effectively preventing the formation of fibrin monomers, which remain in the plasma. The serum is coagulated by the blood, fibrinogen into fibrin monomer hydrolysis, and consumption due to coagulation, centrifugation with the blood cells were separated out. Therefore, the total protein content in plasma is the total protein content of fibrinogen, whereas the total protein content of serum that does not contain fibrinogen should theoretically be lower than the total protein content of plasma. Therefore, in the determination of total blood protein content, the best serum samples, for some emergency specimens, or some other urgent need for determination of patients need to use plasma samples for the determination of total protein, measured in the total protein, Should deduct the content of fibrinogen (usually deducted 3% to 5%), so as to be consistent with the total protein content measured in serum samples, the actual content of the actual body of the patient's total protein.