Transfusion service (TS) laboratories use different protocols to exclude antibodies. For example:
- For antibodies whose corresponding antigens exhibit dosage, some laboratories exclude them based on a negative reaction with one homozygous cell.* Other laboratories require negatives with two homozygous cells to increase the confidence that the antibody is not present.
- If a homozygous cell is not available, some laboratories exclude such antibodies based on a negative reaction with two heterozygous cells.* Other laboratories require negatives with three heterozygous cells to increase confidence that the antibody is not present.
* Homozygous and heterozygous do not refer to the red cells per se but to the red cell donors who are homozygous or heterozygous for the genes that determine the red cell phenotypes.
See the general antibody exclusion protocol to be used in this case.
Antibody exclusion protocol [click to view / print]
Adobe Acrobat PDF file