blood group-specific substances A and B

n.
  1. A solution of complexes of polysaccharides and amino acids that is used to render group O blood reasonably safe for transfusion into persons of group A, B, or AB.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.