What is the order of the colors of blood collection tubes?

I believe that most people have the experience of donating blood. Even if you have never donated blood, you must have gone to the hospital for a blood test. For example, when students have a physical examination for admission, or when they join a new company, there is usually a physical examination process, which includes a blood test. In medicine, there are very strict regulations on the color of blood vessels for blood collection, and usually the following color order must be followed.

The order of blood collection tube colors:

1. Red cap: ordinary serum tube;

2. Orange-red cap: Rapid serum tube, the blood collection tube contains a coagulant to accelerate the coagulation process.

3. Golden red cap: inert separation gel coagulation tube, inert separation gel and coagulant are added to the blood collection tube;

4. Green head cap: Heparin anticoagulant tube, heparin is added to the blood collection tube;

5. Light green cap: plasma separation tube. Adding lithium heparin anticoagulant into the inert separation tube can achieve the purpose of rapid plasma separation.

6. Purple head cap: EDTA anticoagulant tube, ethylenediaminetetraacetic acid (EDTA, molecular weight 292) and its salt are an aminopolycarboxylic acid that can effectively chelate calcium ions in blood samples. Chelating calcium or removing calcium reaction sites will block and terminate the endogenous or exogenous coagulation process, thereby preventing the blood sample from coagulating.

7. Light blue cap: Sodium citrate coagulation test tube. Sodium citrate mainly acts as an anticoagulant by chelating with calcium ions in the blood sample.

8. Black head cover: Sodium citrate erythrocyte sedimentation test tube. The sodium citrate concentration required for the erythrocyte sedimentation test is 3.2% (equivalent to 0.109 mol/L) and the ratio of anticoagulant to blood is 1:4.

9. Gray head cap: Potassium oxalate/sodium fluoride. Sodium fluoride is a weak anticoagulant and is usually used in combination with potassium oxalate or sodium iodate. It is a good preservative for blood glucose determination. It cannot be used for urease determination of urea, nor for alkaline phosphatase and amylase determination. It is recommended for blood glucose testing.

As for the order of blood collection and distribution of multiple tubes, if glass test tubes are used, the order is: blood culture tubes, serum tubes without anticoagulant, sodium citrate anticoagulant tubes, and other anticoagulant tubes; the order is: blood culture tubes (yellow), sodium citrate anticoagulant tubes (blue), serum tubes with or without blood coagulation activators or gel separation, heparin tubes with or without gel (green), EDTA anticoagulant tubes (purple), and tubes with blood glucose decomposition inhibitors (gray).