2.7. Reagents

Phosphate buffered serology saline (PBSS) pH 7.0 [Biosciences] was used for dilution to improve reaction patterns. ²² RBC typing and antibody screening was performed by an enzyme technique ²² using Bromelain [Sigma‐Aldrich], a proteolytic enzyme used daily at a 0.1% working solution.

The five reagent RBCs (rRBCs) required were prepared from RBC packs with known phenotypes on a daily basis. RBCs were washed and prepared in saline suspension at concentrations of 1.25%‐1.45%, depending on the validated RBC concentration required for the relevant profile on the PK7300's.

An O R₁R₁ K+/K‐ and an O R₂R₂ K+/K‐ rRBC were used for antibody screening and an A₁B rRBC was used to detect anti A,B high titer positive donors on the ABOa profile.

The testing of the donor plasma for its hypothetical ABO antibody/ ies (reverse group) was performed using A₁ RhD‐ and B RhD‐ rRBCs on the ABOb profile.