Erythrocytes carry a large negative charge on their surface to avoid spontaneous agglutination. When erythrocytes are suspended in electrolytes, cations are attracted by the negative charge of the erythrocytes, which are just surrounded by a diffuse double-layer ion cloud, and a zeta potential is formed, which determines the repulsion between erythrocytes.
Operation method
Polygel cross-matching assay
Principle
Erythrocytes carry a large negative charge on their surface to avoid spontaneous agglutination. When red blood cells are suspended in an electrolyte, cations are attracted to the negative charge of the red blood cells, and the red blood cells are just surrounded by a diffuse double-layered cloud of ions, resulting in the formation of a zeta potential, which determines the repulsion between red blood cells.
Materials and Instruments
serums Move I. Cross-matching blood test Caveat 1. Plasma containing EDTA can be used instead of serum. 2、If the patient's serum (plasma) contains heparin, such as dialysis patients, must add 4-6 drops of polybrene solution to neutralize heparin. 3. The operation method of this kit is also applicable to antibody identification. 4、Please return to room temperature before using the reagent. 5. The purpose of the auxiliary antiglobulin test is to increase the sensitivity of the detection of anti-K, which is not helpful for the detection of other erythrocyte antibodies. 6. In winter, when the temperature is very low, the serum of some patients may contain cold agglutinin and other factors, which may lead to false-positive results. If there is such a suspicion, it is recommended that the test tube be put into a 37℃ water bath immediately when the last drop is put into the Resuspending, and then gently rotate the tube to mix it and observe the results within 30 seconds. 7， BaSO blood bank special centrifugation 1000g centrifugal force equivalent to 3000 γpm above referred to ordinary centrifuges away from the general 80 centrifuges, the equivalent centrifugal force corresponds to the rotational speed of 3400 γpm. For more product details, please visit Aladdin Scientific website.
test tubes
1, take 2 test tubes, labeled primary and secondary side. Add 2 drops of patient's serum (plasma) to the primary tube, and 3 drops of the blood donor's blood to the primary tube.
5% red blood cell suspension (washed or unwashed can be) 1 drop, the secondary side of the reverse.
2. Add 0.7 ml of LIM to each tube, mix well, and then add 2 drops of Polybrene solution to each tube and mix well.
3, with the blood bank special centrifuge 1000g centrifugal force, centrifugation 1O seconds, (if you use ordinary centrifuge, centrifugation conditions: 3400rpm centrifugation 1O seconds) and then pour off the supernatant, do not drain to let the bottom of the tube residue of about 0.1ml of liquid.
4, gently shake the test tube, visual inspection of red blood cells with or without agglutination, such as no agglutination must be reworked.
5、Finally add 2 drops of Resuspending. Gently rotate the test tube to mix and observe the results at the same time. If the agglutination disperses within 30s, it represents the non-specific focusing caused by Polybrene, and the results of blood matching are compatible; if the agglutination does not disperse, it is the specific reaction of antigen-antibody binding of erythrocytes, and the results of blood matching are not compatible; if the reaction can be coagulated, it can be further poured on the slide and observed by microscope.
Second, blood group determination
1, take the test tube and label, add 2 drops of known diagnostic serum, and then add the person to be examined 3-5% red blood cell suspension (washing or not washing can be) l drop.
2, add LIMO.7 ml and mix well, then add 2 drops of Polybrene and mix well.
3, with BaSO blood bank centrifuge 1000g centrifugal force, centrifugation for 10 seconds (if the use of ordinary centrifuge centrifugation conditions: 3400rpm centrifugation for 10 seconds) and then the supernatant is poured off, do not drain. Leave about 0.1 ml of liquid at the bottom of the tube.
4, gently shake the test tube. Visual inspection of red blood cells with or without agglutination, such as no agglutination must be reworked.
5, finally add 2 drops of Resuspending, gently turn the test tube to mix and observe the results, such as agglutination dispersed, the results are negative, such as agglutination does not disperse results are positive.