• Phase 1: The RBC sensitization phase and the reversible, non-specific polybrene- induced agglutination phase are done simultaneously in a Low Ionic Medium-Polybrene solution (LIMP). The LIMP causes the approximation of the RBC and consequently permits the cross-bridge formation by antibody molecules.
• Phase 2: The reversible, non-specific polybrene-induced RBC aggregates are dispersed by the addition of sodium citrate. The presence of RBC antibody is recognized by the persistent immunological agglutination after the neutralization of the polybrene effect.

In order to detect anti-Kell antibody, a supplementary antiglobulin phase may be performed.