Classification of vacuum blood collection tubes, principle and function of additives

The vacuum blood collection device consists of three parts: a vacuum blood collection tube, a blood collection needle (including a straight needle and a scalp blood collection needle), and a needle holder. The vacuum blood collection tube is its main component, which is mainly used for blood collection and preservation. A certain amount of negative pressure is preset in the production process. When the blood collection needle is punctured into the blood vessel, due to the negative pressure in the blood collection tube, the blood flows automatically. In the blood collection tube; at the same time, various additives are preset in the blood collection tube, which can fully meet a number of comprehensive clinical blood tests, and is safe, closed, and convenient for transportation.
Vacuum blood collection tubes are generally divided into the following categories:

1. Dry empty tube without additives: The inner wall of the blood collection tube is evenly coated with a drug (silicon oil) to prevent wall hanging. It uses the principle of natural blood coagulation to coagulate blood, and after the serum is naturally precipitated, it is centrifuged for use. Mainly used for serum biochemistry (liver function, kidney function, myocardial enzyme, amylase, etc.), electrolytes (serum potassium, sodium, chloride, calcium, phosphorus, etc.), thyroid function, drug testing, AIDS testing, tumor markers, serum immunity learn.

2. Coagulation tube: The inner wall of the blood collection tube is evenly coated with silicone oil to prevent wall hanging, and a coagulant is added at the same time. Coagulants can activate fibrin, turn soluble fibrin into insoluble fibrin aggregates, and then form stable fibrin clots. If you want to get results faster, you can use coagulation tubes. Generally used for emergency biochemistry.

3. Blood collection tube containing separation gel and coagulant: the tube wall is siliconized and coated with coagulant to accelerate blood coagulation and shorten the test time. Separation gel is added in the tube. Separation gel has good affinity with PET tube, and it does play a role in isolation. Generally, even in ordinary centrifuges, the separation gel can separate the liquid components (serum) and solid components (blood cells) in the blood. Separate completely and accumulate in the tube to form a barrier. No oil droplets are produced in the serum after centrifugation, so it does not clog the machine. Mainly used for serum biochemistry (liver function, kidney function, myocardial enzyme, amylase, etc.), electrolytes (serum potassium, sodium, chloride, calcium, phosphorus, etc.), thyroid function, drug testing, AIDS testing, tumor markers, serum immunity learn.

4. Blood collection tubes with anticoagulant in the tube:
1) Blood collection tubes containing sodium heparin or lithium heparin: Heparin is a mucopolysaccharide containing sulfate groups with a strong negative charge, which has the effect of strengthening antithrombin III to inactivate serine protease, thereby preventing thrombin Formation, and has anticoagulant effects such as preventing platelet aggregation. Heparin tubes are generally used for emergency biochemical and blood flow detection, and are the best choice for electrolyte detection. When testing sodium ions in blood samples, heparin sodium should not be used, so as not to affect the test results. It also cannot be used for leukocyte counting and differentiation, as heparin can cause leukocyte aggregation.

2) Blood collection tubes containing EDTA and its salts (EDTA—): EDTA is an amino polycarboxylic acid, which can effectively chelate calcium ions in the blood, and chelating calcium will remove calcium from calcium. The removal of the reaction point will prevent and terminate the endogenous or extrinsic coagulation process, thereby preventing blood coagulation. Compared with other anticoagulants, it has less influence on the coagulation of blood cells and the morphology of blood cells, so EDTA salt is usually used. (2K, 3K, 2Na) as anticoagulants. It is used for general hematological examinations, and cannot be used for blood coagulation, trace elements and PCR examinations.

3) Blood collection tubes containing sodium citrate anticoagulant: Sodium citrate plays an anticoagulant effect by acting on the chelation of calcium ions in the blood sample. The ratio of agent to blood is 1:9, and it is mainly used in the fibrinolytic system (prothrombin time, thrombin time, activated partial thrombin time, fibrinogen). When collecting blood, pay attention to the amount of blood collected to ensure the accuracy of the test results. Immediately after blood collection, it should be inverted and mixed 5-8 times.

4) Contains sodium citrate, the concentration of sodium citrate is 3.2% (0.109mol/L) and 3.8%, the volume ratio of anticoagulant to blood is 1:4, generally used for ESR detection, the proportion of anticoagulant is too high When it is high, the blood is diluted, which can speed up the erythrocyte sedimentation rate. This article comes from the inspection zone network

5) The tube contains potassium oxalate/sodium fluoride (1 part of sodium fluoride and 3 parts of potassium oxalate): Sodium fluoride is a weak anticoagulant, which has a good effect on preventing blood sugar degradation, and is an excellent preservative for blood sugar detection. Care should be taken to invert and mix slowly when using. It is generally used for blood sugar detection, not for the determination of urea by urease method, nor for the detection of alkaline phosphatase and amylase.