Biosynthesis of a blood-group-I determinant reacting with anti-I Ma serum (group 1)

A blood-group-I determinant reacting specifically with anti-I Ma serum (group 1) has been produced biosynthetically by the action of a beta-galactosyl transferase isolated from human milk on a precursor glycoprotein produced by formic acid hydrolysis and beta-D-galactosidase action on blood-group H substance prepared from hog gastric mucosa.