In clinical diagnosis, taking a blood sample for analysis is a very common aid. Improper handling of blood samples may cause larger errors than analysis when blood is collected for analysis. Therefore, an appropriate anticoagulant and treatment method should be selected according to the purpose of the analysis. The application of physical or chemical methods to remove or inhibit certain coagulation factors in the blood and prevent blood coagulation is called anticoagulation. Chemical agents that stop blood from clotting are called anticoagulants. The general requirements for anticoagulants are that the dosage is small, the solubility is large, and the determination is not affected. Blood collection tubes are divided into three types: ordinary tubes, anticoagulation tubes and coagulation tubes. According to different test items, it is very important to choose the appropriate anticoagulant.

Ⅰ. Ordinary blood collection tubes

Red cap, no additives in the blood collection tube, used for routine serum biochemical and serological related tests.

Ⅱ. Coagulation blood collection tubes

1. Rapid blood collection tubes

Orange-red head cover, there is a coagulant in the blood collection tube, which can activate fibrin, turn soluble fibrin into insoluble fibrin polymer, and then form a stable fibrin clot. The rapid blood collection tube can coagulate the collected blood within 5 minutes, and is suitable for emergency serum biochemical tests.

2. Inert separation gel accelerator tubes

Golden cap, inert separating gel and coagulant are added to the blood collection tube. After the sample is centrifuged, the inert separation gel can completely separate the liquid components (serum or plasma) and solid components (red blood cells, white blood cells, platelets, fibrin, etc.) in the blood and completely accumulate in the center of the test tube to form a barrier. Stablize. Procoagulants can quickly activate the coagulation mechanism and accelerate the coagulation process, and are suitable for emergency serum biochemical tests.

Ⅲ. Anticoagulation blood collection tubes

1. Heparin anticoagulation tubes

Green cap, blood sample collection tubes with heparin added. Heparin is a mucopolysaccharide containing a sulfate group, which has the ability to resist the formation and activity of thromboplastin and thrombin, prevent platelet aggregation, inhibit the conversion of prothrombin into thrombin, and prevent fibrinogen from being converted into fibrin. This prolongs the clotting time of the specimen. Heparin anticoagulation does not affect the volume of red blood cells. It is suitable for red blood cell fragility test, blood gas analysis, hematocrit test, erythrocyte sedimentation rate and general biochemical determination, but it cannot be used for 3P and TT tests for screening DIC. , causing false positives for 3P and interference with the antithrombin effect of heparin. Excessive heparin can cause aggregation of white blood cells and cannot be used for white blood cell counts. It is also not suitable for leukocyte classification because it can make the blood film stained with a light blue background.

2. Plasma separation tube

Light green head cover, adding heparin lithium anticoagulant to the inert separation rubber tube, can achieve the purpose of rapid separation of plasma, is the best choice for electrolyte testing, and can also be used for routine plasma biochemical testing and emergency plasma biochemical testing such as ICU. Plasma samples can be directly put on the machine and kept stable for 48 hours under refrigeration.

3. EDTA anticoagulation tube

Purple caps, EDTA and its salts are aminopolycarboxylic acids that effectively chelate calcium ions in blood samples. Chelating calcium or removing calcium from the reaction site will block and terminate the intrinsic or extrinsic coagulation process, thereby preventing the blood sample from coagulating. It is suitable for general hematological tests, not suitable for coagulation test and platelet function test, nor for the determination of calcium ion, potassium ion, sodium ion, iron ion, alkaline phosphatase, creatine kinase and leucine aminopeptidase and PCR test. EDTA-Li2 can also be used as an anticoagulant and can be used for most biochemical tests.

4. Sodium citrate coagulation test tube

Light blue cap, sodium citrate acts as an anticoagulant mainly by chelating calcium ions in the blood sample. The sodium citrate coagulation test blood collection tube is suitable for coagulation experiments, and the ratio of anticoagulant to blood is 1:9.

5. Sodium citrate ESR test tube

The black cap, the sodium citrate concentration required for the ESR test is 3.2%, and the ratio of anticoagulant to blood is 1:4.