Blood routine examination typically utilizes purple-headed blood collection tubes containing anticoagulants (EDTA tubes). The inner walls of these tubes are coated with ethylenediaminetetraacetic acid (EDTA), which prevents blood coagulation and ensures that the blood sample remains liquid during testing, facilitating the analysis of blood cell count and morphology. Different colored blood collection tubes correspond to different testing items; for example, blue-headed tubes are used for coagulation function tests, while yellow or red-headed tubes are used for biochemical tests.

1. Types and Uses of Blood Collection Tubes

Purple tube (EDTA tube) 1

Specifically for blood routine examination: EDTA prevents the coagulation process by binding to calcium ions in the blood, ensuring the integrity of blood cell morphology.

Applicable testing items: red blood cell count, white blood cell count, platelet count, hemoglobin concentration, and white blood cell classification (such as neutrophil and lymphocyte proportions), etc.

Precautions: After blood collection, gently invert and mix the sample 8-10 times to prevent blood coagulation or cell rupture.

The role of other color tubes 2

Blue tube (sodium citrate tube): used for coagulation function tests (such as prothrombin time).

Green tube (heparin tube): used for emergency biochemical or hemorheology tests.

Yellow/red tube (without anticoagulant or procoagulant): used for serum separation, detection of liver function, blood lipids, etc.

II. Core detection indicators of blood routine examination

Red blood cell-related 1

Hemoglobin (HGB): Reflects oxygen-carrying capacity, and a low level may indicate anemia.

Hematocrit (HCT): The proportion of red blood cell volume in the blood, which aids in the diagnosis of dehydration or anemia.

Leukocyte-related 2

White blood cell count (WBC): An increase is commonly seen in infections and inflammation, while a decrease may be related to low immunity.

Ratio of neutrophils to lymphocytes: It helps distinguish between bacterial infection (neutrophils ↑) and viral infection (lymphocytes ↑).

Platelet-related 3

Platelet count (PLT): A low count may increase the tendency to bleed, while a high count may increase the risk of thrombosis.

III. Inspection Process and Precautions

Preparation before blood collection 1

Usually, fasting is not necessary, but if biochemical tests (such as blood glucose and blood lipids) are to be conducted simultaneously, it is necessary to follow the doctor's advice and fast for 8-12 hours.

Avoid strenuous exercise or emotional stress, as they may temporarily affect the white blood cell or red blood cell count.

Post-blood collection processing 2

The puncture site needs to be pressed for 3-5 minutes to prevent subcutaneous ecchymosis.

The test results are usually issued within 1-2 hours, and abnormal indicators need to be comprehensively judged in combination with symptoms and other examinations.

IV. Common causes of abnormal results

Anemia: It may be caused by iron deficiency, chronic diseases, or bone marrow problems.

Infection or inflammation: An increase in white blood cells is commonly observed in conditions such as pneumonia and tonsillitis.

Platelet abnormalities: Drug side effects, autoimmune diseases, or hematologic diseases may all affect platelet counts.

V. The significance of testing for special populations

Children: Blood routine examination can assist in diagnosing the type of infection or hematological diseases (such as leukemia).

Pregnant women: Monitor for complications such as anemia and gestational thrombocytopenia.

Postoperative patient: Assess blood loss or infection risk.

Through blood routine examination, doctors can quickly understand the basic blood status of patients and provide important basis for diagnosis. If the results are abnormal, further clarification of the cause is needed in combination with clinical manifestations and other examinations.