The detection of blood group phenotypes using paper diagnostics.

BACKGROUND AND OBJECTIVES: Paper biodiagnostics for blood typing are novel, cheap, fast and easy to use. Agglutinated red blood cells cannot travel through the porous structure of paper, indicating a positive antibody-antigen interaction has occurred. Conversely, non-agglutinated blood can disperse and wick through the paper structure with the ease to indicate a negative result. This principle has been demonstrated to detect blood group phenotypes: ABO and RhD. However, typing for red blood cell antigens such as Rh, Kell, Duffy and Kidd has not yet been explored on paper. MATERIALS AND METHODS: Two paper testing methods - an elution and a direct flow-through method - were investigated to detect red blood cell antigens excluding the ABO system and RhD. Antigens explored include the following: C, c, E, e, K, k, Fy(a), Fy(b), Jk(a), Jk(b), M, N, S and s, P1, Le(a) and Le(b). The variables tested include the following: reaction time and reagent concentration. The importance of antibody type/structure for successful agglutination on paper was confirmed. RESULTS: Some blood group phenotypes showed less agglutination due to weaker antibody-antigen interactions. Most blood groups with antibodies available as IgM, such as C, c, E, e, K and k, and Jk(a) and Jk(b), and P1, were successful using both methods. However, other blood groups, especially those with antibodies only available as polyclonal antibodies, were unsuccessful and require further scrutiny. CONCLUSION: Paper can be used as an alternative blood grouping diagnostic tool for selected blood group phenotypes.