Blood Cross Match

Major Cross Match Protocol

Simple test tube method.

1. Remove a segment or several segments from the donor unit.  Squeeze the blood from the segment and centrifuge at the lowest speed for 10 minutes.

2. Aspirate 0.2mls of the packed red blood cells and add it to 4.8 mls of 0.9% normal saline.

3. Put 0.1 mls of this mixture into 3 small glass tubes.

4. Next put 0.1mls of the patient’s serum or plasma into each of the 3 tubes.   Now each tube contains 0.1ml of the donor red cells and 0.1 mls of the patient’s serum or plasma.

5. Incubate 1 tube at room temperature, 1 tube at refrigerator temperature and 1 tube at 37°C.

6. Centrifuge for 1 minute.

7. Examine the supernatant for any hemolysis.

8. Examine the cell button.  Flick the test tubes.  The fluid in the tubes should redden as the cells disperse.

9. If the red cell button is agglutinated examine a drop under low microscopic power.

10. For minor cross match use the patient’s red cells and the donor’s serum or plasma.


For the controls use the patient’s red cells and the patient’s plasma.