Blood group antigens absent:Prid:Pt:RBC^Donor:Nom
blood group antigens absent:prid:pt:rbc^donor:nom
Blood group antigens absent:Presence or Identity:To identify measures at a point in time:Erythrocytes^Donor:Nominal
blood group antigens absent:presence or identity:to identify measures at a point in time:erythrocytes^donor:nominal