Reaction of cold agglutinins with I antigen solubilized from human red cells.

The antigens reacting with cold-aggluantigen and antibody were not able to tinin antibodies and present in the red react at 37#{176}Cwhen the antigen was cell membranes of human red cells were present in the intact cell, after solubilizafound in the water-phase when the tion, antigen and antibody reacted washed membranes were extracted with equally well at 37#{176}Cand at 0#{176}C. The n-butanol. The presence of these antiamount of anti-I inhibiting activity presgens was demonstrated by agglutination ent in extracts from adult and cord cells inhibition, complement fixation, and antiwas roughly the same, although the body inhibition as determined by the Cl amount of antibody fixed to the intact fixation and transfer test. Although cord cells was less with cord cells.