TkPolyagglutination Produced in vifro by an Endo-Beta-Galactoddase

Abstract
After treatment with the culture supernatant of Bacteroides fragilis or with an endo-.beta.-galactosidase from Escherichia freundii, the human red blood cells were Tk-activated, i.e., agglutinable by BS II lectin and their blood group I and i activities were reduced. B. fragilis apparently produces endo-.beta.-galactosidase activity and the main antigenic determinant of Tk polyagglutinable red cells is apparently a terminal N-acetyl-glucosamine residue.