Reagent kit for determining the activity of antithrombin III in human blood plasma by the clotting method ("ReaClot AT III Test") according to TU 9398-023-05595541-2011. The kit is intended for the quantitative determination of antithrombin III activity in blood plasma using the clotting method, both manually and on automatic analyzers.
Antithrombin III (AT III) or heparin cofactor is the main antagonist of thrombin in blood clot formation. Inherited and acquired deficiencies of AT III in the blood lead to the development of disseminated intravascular coagulation (DIC syndrome) and, in some cases, acute thrombosis. Reduced AT III concentration is observed in patients with liver diseases (cirrhosis), nephrotic syndrome due to inhibitor excretion in urine, and is influenced by heparin injections and oral contraceptives.
Method principle: In the tested plasma, fibrinogen is removed by heat treatment, a standard amount of thrombin is added, the mixture is incubated, and then the residual (after interaction with AT III) thrombin activity is determined. Thrombin activity is determined by the clotting time of a standard fibrinogen solution. The higher the AT III activity in the tested plasma, the lower the residual thrombin activity, and the slower the clot formation.
To construct a calibration curve, a defibrinated plasma calibrator is provided. The clotting time in seconds is plotted on the Y-axis on a logarithmic scale, and AT III activity in % is plotted on the X-axis on a linear scale.
Using the calibration curve and the clotting time value of the test sample, the AT III activity in % is determined.
Composition of the kit:
One kit is intended for conducting 160 determinations manually on a semi-automatic coagulometer. The number of analyses on automatic analyzers depends on the instrument's design.
Normal and pathological values of antithrombin III activity should be monitored using the reagent "Control Plasma (pool of healthy donors) (Plasma N)," code KM-1.