The speed of medical tests is of great clinical significance. Some tests require the separation of serum from blood concentration in order to perform. It usually takes one hour from blood clotting to hemorrhage extraction. Even if heated centrifugation is used, it takes half an hour, and it is easy to cause hemolysis. In case of emergency blood distribution or emergency diagnosis, delay time and delay treatment. Therefore, shortening the time of serum separation is an urgent problem to be solved in the current inspection work. In this case, blood coagulant was born.
Blood coagulation:
(1) The concept of promoting coagulation: The process of accelerating blood coagulation by introducing some substances is blood coagulation.
(2) Blood coagulant: substances that can accelerate blood coagulation are called blood coagulants. Blood coagulants include silica powder, glass, fiber, hair, thrombin, snake venom, and rabbit brain powder.
(3) The principle of blood coagulation: blood coagulation is referred to as coagulation, which is the process of changing blood from a flowing state to a gel state. It is an important part of the hemostatic function. The coagulation process is a process in which a series of coagulation factors are activated by successive enzymatic hydrolysis, and finally generates thrombin, forming a fibrin clot. There are 14 factors involved in coagulation. Among them, there are 12 numbered with Roman numerals (from I to VIII, of which factor VI does not exist).
The coagulation process is usually divided into: ① endogenous coagulation pathway; ② exogenous coagulation pathway; ③ common coagulation pathway.
Vacuum blood collection tubes with coagulants sometimes have filaments and lumps precipitated by fibrin, which are caused by the lack of standardized use of coagulant blood collection tubes. In the preparation of vacuum blood collection tubes, the selection of procoagulants with too fast coagulation speed will cause fibrin to contract too fast and the fragile red blood cells to break easily, causing mild hemolysis. There are the following reasons for the precipitation of fibrin: the use of coagulant blood collection tubes or separation gel to promote coagulation blood collection tubes, if the coagulant is evenly distributed in the blood, it must be slightly inverted and mixed 4-5 times, so that the center of the blood collection tube and the surrounding The blood coagulates at the same time. If the blood is not completely coagulated, it is centrifuged, which can cause the precipitation of fibrin. A jelly sample or a lump sample appeared on the upper part of the serum, mixed with blood. Fibrin filaments are caused by fibrin that has not contracted completely. When using coagulant blood collection tubes, the spraying of coagulant is insufficient or the prepared water-soluble coagulant is not used up on the same day, and the continued use the next day leads to a decrease in the effectiveness of the coagulant. Fibrinogen in the blood is gradually transformed into insoluble fibrin under the action of a coagulant. If the dose of the coagulant is insufficient or fails to extend the coagulation time, centrifugation can cause fibrin precipitation.
