blood typing

The ABO blood group system is mainly named according to the different agglutinogens (ie, blood type antigens, three types of A, B, and H) contained on the surface of human red blood cells. ABO blood group identification refers to the detection of ABH blood group antigen. The red blood cells contain the A antigen called type A, the B antigen type called type B, the A and B antigens called AB type; the A and B antigens are not included, and the H antigen is called the O type. Type A human serum contains only anti-B antibody; type B serum contains only anti-A antibody; AB type serum has no anti-A and anti-B antibodies; and type O serum has anti-A and anti-B antibodies. Standard anti-A and anti-B sera were used to identify antigens on the red blood cells of the subjects (direct test); and standard A-type and B-type red blood cells were used to identify antibodies in the serum of the subjects (reverse test). Only when the results of antigen identification on the red blood cells of the subject and the identification of antibodies in the serum are completely consistent can the blood type category be confirmed. Basic Information Specialist classification: growth and development examination classification: blood examination Applicable gender: whether men and women apply fasting: not fasting Tips: If blood type is inconsistent during blood transfusion, it can cause serious antigen-antibody reaction in the patient's body. A large number of red blood cells are destroyed, causing hemolysis and endangering life. Normal value The blood type of the examiner is judged based on the phenomenon. ABO blood type is divided into A type, B type, O type, AB type. Clinical significance ABO blood type identification is mainly used for (1) Clinical blood transfusion When circulating blood volume is insufficient or blood loss or anemia is required for transfusion therapy, blood donors with the same blood type must be selected before blood transfusion, and cross-matching blood can be performed. In case of emergency, when blood type must be used, patients with AB blood type can accept other blood types, but type B blood is preferred and used as little as possible. Type A blood has many subtypes, which are prone to cause transfusion reactions, so try not to lose to patients with heterotypic blood. When an O-type mother gives birth to a type A or type B fetus, blood transfusion is required during pregnancy, and blood transfusion must be adhered to. (2) When transplanting organs such as skin, bone marrow, and kidney transplantation, select a donor with ABO blood type matching. (3) Analysis of the causes of infertility and neonatal hemolysis. (4) Paternity test. Forensic is used to deny parent-child relationships. For example, one parent is O-type, the other is A or B-type, the child is not AB-type, the child will have a parent's blood type; the parents are O-type, the child can only be O-type; the parent is AB-type, child It will not be O type; parents are O type and AB type, children cannot be O type or AB type; parents are type A, children can only be type A or type O; parents are type B, children can only be Type B or O type. When the blood type of the child is in accordance with the genetic law, it is difficult to affirm the parent-child relationship, and it is necessary to use the human leukocyte antigen test to infer that the parent-child relationship index may occur. Precautions 1. If blood type is inconsistent during blood transfusion, it can cause serious antigen-antibody reaction in the patient's body, and a large number of red blood cells are destroyed, causing hemolysis and endangering life. 2, maternal and child ABO blood group incompatibility can cause neonatal hemolytic disease. 3. The blood type of the donor and the recipient is not compatible during organ transplantation, and hyperacute rejection may occur. Inspection process Test tube method (positive, inverse type) (1) Take 3 clean small test tubes, which are labeled with anti-A, anti-B and anti-AB, respectively, and add 1 drop of anti-A, anti-B and anti-A and B-type serum to the test tube with a dropper. At the bottom, add 1 drop of 2% red blood cell suspension to the subject with a dropper and mix (positive type). (2) Take another 3 small clean test tubes, mark A, B, and O respectively, add 1 drop of serum to the bottom of the test tube with a dropper, and add 2% A, B, and O reagents respectively to the dropper. 1 drop of red blood cell suspension, mix (reverse). (3) Immediately at 1000 rpm/separation of the heart for 1 min, gently shake the test tube to float the red blood cells sinking at the bottom of the tube, and observe whether there is agglutination or hemolysis by the naked eye and microscope. The blood type is judged based on the result. Not suitable for the crowd 1. Patients who have taken contraceptives, thyroid hormones, steroid hormones, etc., may affect the results of the examination and prohibit patients who have recently taken the drug history. 2, special diseases: patients with hematopoietic function to reduce disease, such as leukemia, various anemia, myelodysplastic syndrome, etc., unless the examination is essential, try to draw less blood. Adverse reactions and risks 1, subcutaneous hemorrhage: due to pressing time less than 5 minutes or blood draw technology is not enough, etc. can cause subcutaneous bleeding. 2, discomfort: the puncture site may appear pain, swelling, tenderness, subcutaneous ecchymosis visible to the naked eye. 3, dizzy or fainting: in the blood draw, due to emotional overstress, fear, reflex caused by vagus nerve excitement, blood pressure decreased, etc. caused by insufficient blood supply to the brain caused by fainting or dizziness. 4. Risk of infection: If you use an unclean needle, you may be at risk of infection.