The test of serologic compatibility considering the recipient and the donor carried out before transfusion
1. Collect blood sample of 2ml with EDTA from a donor
2. The blood samples collected from a donor and a recipient should be centrifuged and the plasma should be distracted to separate test tubes
3. The blood cells obtained from donor and recipient (without clots) should be washed out twice with 0.9% NaCl (pour great amount of NaCl to the test tube containing blood, then centrifuge, decant the supernatant and pour NaCl, centrifuge again and at last decant the supernatant)
4. Prepare 3-4% suspension from the washed out blood cells with NaCl (1 drop of dense blood cells and 24 drops of NaCl)
5. Carry out the compatibility test by dotting the suspension on glasses:
a) 1 drop of recipient’s serum + 1 drop of donor’s blood cells
b) 1 drop of donor’s serum + 1 drop of recipient’s blood cells
c) 1 drop of recipient’s serum + 1 drop of recipient’s blood cells- AUTOCONTROL
The results are estimated after 30 minutes by moving the glass in a gentle way.
The test is compatible when there is no agglutination or haemolysis observed. If the results are difficult to estimate, the microscope should be used to study the preparation in detail. It is helpful to differentiate agglutination from rolling. Presence of rolling either in compatibility test or in autocontrol allows to estimate the test as compatible.
Rolling observed microscopically: Blood cells arrange in characteristic rolls. To confirm the presence of rolling (not agglutination) NaCl (2 drops) should be added to the sample.