Blood Types

• The presence of absence of specific surface antigens in RBS plasma membrane determines an individual's blood type
• Surface antigens are glycoproteins, and are genetically determined
• Three surface antigens of particular importance: A, B, and Rh (D)
• The red blood cells of each person have a characteristic combination of surface antigens
• • Antigen A makes blood type A
  • Antigen B makes blood type B
  • Antigen A and B makes blood type AB
  • No antigen A or B makes blood type O
• The Rh blood group is based on the presence or absence of the Rh surface antigen
• Rh positive (Rh+) indicates the presence of the antigen, called the Rh factor
• Rh negative (Rh-) indicates the absence of the antigen