Precipitation Reaction between Serum and Lysed Erythrocytes

Abstract

HUMAN serum reacts with hæmolysates of human erythrocytes to form a precipitate ; this occurs even with the isologous hæmolysate. When the hæmolysate is added to serum in tubes at 37° C., precipitation continues for several days. In agar-gel, using a double diffusion technique, a well-marked precipitate band is formed (Fig. 1). Peetoom et al. ¹ described a precipitate of this type in agar-gel, but only minimal precipitation in fluid media. In spite of antigenic differences between adult and fœtal hæmoglobins², serum and hæmolysate from adult and umbilical cord blood form precipitates in agar-gel, which are qualitatively the same. Cross-precipitation also occurs between human and some animal sera and hæmolysates. As the reaction is of general occurrence, it causes false positive results in tests for auto-antibodies when the tissue extract used as antigen contains sufficient lysed erythrocytes.