ABO and Rh Typing

• ABO and Rh Typing


  Determination of a person's blood group through detection of antigens on red blood cell surface
• ABO and Rh


  • Most common human blood group systems
  • Implicated with transfusion-associated morbidities/mortalities and severe HDFN/erythroblastosis fetalis
• ABO Forward Typing (Slide Method)


  1. Place one drop of each antisera on a glass slide separately

  2. Add one drop of blood to each antisera on the slide

  3. Mix the antisera and blood sample

  4. Observe for agglutination of RBCs
• Antisera


  Used to determine which antigens are on the red cells
• ABO Phenotype


  • A
  • B
  • AB
  • O
• Antibodies in Plasma


  • Anti-B
  • Anti-A
  • None
  • Anti-A and Anti-B
• Frequencies of ABO groups in the population: Type O = 40%, Type B = 28%, Type A = 23%, Type AB = least common 3%
• Rh Typing (Slide Method)


  Based on the detection of D antigen on the surface of the RBCs
• Rh Typing (Slide Method)

  1. Place one drop of each antisera on a glass slide separately

  2. Add one drop of blood to each antisera on the slide

  3. Mix the antisera and blood sample

  4. Observe for agglutination of RBCs
• Rh-positive


  1. antigen present
• Rh-negative


  1. antigen absent
• What blood type is known as the universal donor?

  O
• What antibodies are present in the plasma of a person with type A blood?

  Anti-B antibodies
• What does the presence of the Rh factor on red blood cells indicate?

  The blood type is Rh positive.
• Why is a person with AB+ blood considered the universal recipient?

  They have no anti-A, anti-B, or anti-Rh antibodies, so they can receive any blood type.
• When is Rh incompatibility during pregnancy a concern?

  When the mother is Rh-negative and the baby is Rh-positive.
• True or False: A person with AB+ blood can receive blood from any ABO or Rh type.

  True
• What antibodies are present in the plasma of a person with type A blood?

  Anti-B antibodies
• Which blood types can a person with B- blood safely receive?

  B- and O-
• True or False: A person with O+ blood can donate to anyone with a positive Rh factor.

  True
• Why is a person with AB+ blood considered the universal recipient?

  They have no anti-A, anti-B, or anti-Rh antibodies, so they can receive any blood type.
• True or False: The ABO blood group system is determined by the presence or absence of specific antibodies in the plasma.

  False (It is determined by the presence or absence of antigens on the surface of red blood cells.)