A Blood Bank in southeastern Pennsylvania centifuges blood samples that are submitted for pre-transfusion testing, and aliquots the plasma or serum from the centrifuged sample into a labeled daughter tube. The red cells of the sample remain in the primary collection tube. The plasma or serum in the secondary tube is used for ABO backtyping, antibody detection testing, and crossmatching. The red cells of the primary tube are used for ABO forward grouping. At a recent inspection of this facility an inspector noted this using a separate secondary tube for the serum/plasma was "no longer necessary and may lead to plasma or serum being placed in the wrong aliquot tube when working on multiple samples at the same time". The inquiring Blood Bank would like to know how other blood banks manage their pre-transfusion samples.

The following responses have been received.

ADDENDA July 21, 2003

1. An Australian colleague reports that his laboratory uses EDTA samples and these are kept as a centrifuged primary tube throughout their storage period. They support the statement that this is a safer option than making up 'daughter tubes'. This has been their practice for at least 10 years without incident.

2. A laboratory colleague in New Jersey reports that two years ago, her laboratory stopped separating serum/plasma from the red cells and storing the separated aliquot in a daughter tube. They made this change because of a few instances where they discovered that an incorrect serum aliquot ('daughter') tube had been attached to the original tube. Now they remove enough plasma to perform immediate tests, and leave the rest of the serum in the original tube on the red cells. They discard the aliquot tube when immediate testing is complete. They have done parallel testing and have found no difference with results, except occasional auto-absorption of cold autoantibodies, which the responding colleague is not unhappy about.

ADDENDA July 28, 2003

3. A Canadian colleague reports that her hospital handles pre-transfusion samples by labeling the primary tube (no separation of the sample into plasma/serum aliquots) for testing and storage purposes. This approach has been in place for all of their Transfusion laboratory sites for approximately five years; the decision was made for both practical (lack of sufficient storage space in refrigerators and freezers) and safety (decreasing process issues that could lead to further errors) reasons.

Please submit comments to the e-Network Forum.

Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator