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(5) Rh-positive blood should be selected for Rh-positive recipients.
(6) Rh-negative blood should be saved for Rh-negative recipients (this includes individuals that
are D-positive).
NOTE: If a person is Du positive, his blood will be considered Rh-positive if he is a donor and
considered Rh-negative if he is a recipient.
- Prepare the equipment.
a. Obtain the test tube rack.
b. Place the patient’s blood specimen tube and serum tube in the rack.
c. Obtain two test tubes; label and place them in the rack.
(1) Label tube #1, “XM” (Crossmatch) with the patient’s ID number.
(2) Label tube #2, “AUTO” (Auto Control) with the patient’s ID number.
d. Prepare a 2% to 5% cell suspension from a segment of the donor unit and the recipient’s
cells. - Prepare the tubes for testing.
a. Add 2 drops of recipient serum and 1 drop of donor cell suspension to the tube labeled “XM”.
b. Add 2 drops of recipient serum and 1 drop of recipient cell suspension to the tube labeled “AUTO”. - Prepare the test tubes for an immediate spin (saline phase).
a. Mix the test tubes.
b. Centrifuge the test tubes for 15 seconds.
c. Examine each test tube for agglutination.
NOTE: If the recipient has a negative antibody screen, the current standards suggest that an
immediate spin crossmatch be performed ONLY for the detection of ABO incompatibilities. The
antiglobulin phase of testing rarely uncovers clinically significant antibodies in a recipient whose
antibody screening test is negative.
(1) Write on the work sheet “+” for agglutination.
NOTE: Grade the degree of agglutination: +/=, 1+, 2+, 3+, or 4+.
(2) Write on the work sheet “=” for no agglutination.
WARNING: If a positive reaction occurs in the crossmatch, STOP the crossmatch procedure. The
blood is not compatible. - Perform the albumin phase.
a. Add 2 drops of 22% bovine albumin to tubes labeled “XM” (only if no agglutination appeared
after saline phase) and “AUTO”.
b. Mix the tubes.
c. Centrifuge the test tubes for 15 seconds.
d. Examine the test tubes for agglutination.
(1) Write on the work sheet “+” for agglutination.
NOTE: Grade the degree of agglutination: +/=, 1+, 2+, 3+, or 4+.
(2) Write on the work sheet “=” for no agglutination.
WARNING: If a positive reaction occurs in the crossmatch, STOP the crossmatch procedure: the
blood is not compatible. - Continue testing tubes “XM” and “AUTO”.
a. Incubate the test tubes for 15 to 30 minutes at 37ø C.
b. Centrifuge the test tubes for 15 seconds.
c. Examine each test tube for agglutination.
(1) Write on the work sheet “+” for agglutination.
NOTE: Grade the degree of agglutination: +/=, 1+, 2+, 3+, or 4+.
(2) Write on the work sheet “=” for no agglutination. - Perform the final testing of tubes “XM” and “AUTO”.
a. Wash the tubes four times with saline.
b. Remove all saline from the last wash.
c. Add 2 drops of antihuman globulin to both tubes.
d. Mix the tubes.
e. Centrifuge the test tubes for 15 seconds.