Solid‐phase ABO grouping and Rh typing

Abstract
A solid‐phase adherence method (SPAM) for ABO grouping and Rh typing of red cells (RBCs) has been developed. Adherence reactions were read spectrophotometrically and interpreted by a computer. The SPAM had a 99.6 percent correlation with conventional microplate agglutination methods for ABO grouping and Rh typing. The increased sensitivity of the SPAM was demonstrated because it directly detected Du‐positive RBCs and weak subgroups of A and B.