A process for the detection of antibodies in a test sample by preparing a suspension of erythrocytes with a test serum or plasma by mixing a test serum or plasma with erythrocytes; incubating the suspension of erythrocytes at a temperature of from 37° C. to 45° C. to bind any antibodies in the test serum or plasma to the surface of said erythrocytes; combining the suspension of erythrocytes with an amount of a solution of a macromolecule which is effective to agglutinate the erythrocytes; packing the resultant red cell agglutinates by centrifuging the suspension of erythrocytes; and, determining the presence of anti-erythrocyte antibodies by observing if antibody-dependent erythrocyte agglutination has occurred.