(a) The second tube may be left, as in Steps 1 and 2; add 2 to 3 drops
of 22 to 30 percent albumin, according to manufacturer's directions; mix. Centrifuge,
read and record results.
Incubate the second tube 15 to 80 minutes, at 37C.
(c) Centrifuge immediately upon removing from the incubator.
Examine for hemolysis, agglutination, read and record results.
(d) Wash 3 or 4 times with saline. After the last wash, decant
completely. Add 1 to 2 drops antiglobulin serum and mix.
(e) Centrifuge; examine for agglutination with an optical aid; record
results. (Optical aid is optional.)
(f) Add 1 drop of known sensitized cells to all negative test.
Centrifuge; examine for agglutination record result. If no agglutination is seen, the
antiglobulin test must be repeated.
e. Immediate Spin Technique. By AABB standards, minimal serological
testing, (saline crossmatch), is an acceptable method to demonstrate ABO
incompatibilities between the donor and the recipient if:
Antibody detection is negative on the recipient, and/or,
Recipient has no clinical significant antibodies.
1-48. INCOMPATIBLE CROSSMATCH
(1) When incompatibility is seen in an early phase of a cross-match, the
testing should be completed to give information as to temperatures media where
reactions occur, the variability of these reactions, and the percentage of incompatible
donors. These clues will aid in choosing correct conditions for antibody identification.
(2) It is preferable to determine the cause of the incompatibility, rather than
to continue blindly. If the need for transfusion is too urgent for this course of action,
many random units may be crossmatched. If possible, attempts to identify the antibody
should be started while the crossmatch is being completed.