Typing reagents for hybrid glycophorin blood groups that are rare in Caucasians, but with prevalence of up to 8% in East Asian ethnic groups, are unavailable despite repeated attempts by various groups to use conventional approaches to produce useful mAbs. We will utilise naive human phage libraries to develop reagents that react with RBC with a phenotype defined by the most common hybrid glycophorin but not with pooled human RBC that do not display these antigens. The usefulness of the mAb produced as a typing reagent will be assessed by binding to the target hybrid glycophorin detected by flow cytometry. Subsequently reactivity using the standard immunohaematological agglutination based techniques will be assessed as well as characterising other features required for typing reagents, such as long term stability at room temperature.