Lec 11 b

• What is the purpose of cross-matching before a blood transfusion?

  To ensure that there are no antibodies in the patient’s serum that will react with the donor’s cells.
• What are the types of cross-match in blood transfusion?

  • Major cross-match: Red cells from donor and serum from recipient.
  • Minor cross-match: Serum from donor and red cells from recipient.
• What does the major cross-match detect?

  It detects antibodies in the recipient's serum against the donor's red cells.
• What does the minor cross-match detect?

  It detects antibodies in the donor's serum against the recipient's red cells.
• What is the saline cross-match technique used for?

  To detect IgM antibodies.
• What type of antibodies does the albumin technique detect?

  IgG antibodies.
• What type of antibodies does the enzyme technique detect?

  IgG and some IgM antibodies.
• What type of antibodies does the antiglobulin test or Coombs test detect?

  IgG antibodies.
• What are the steps in the major cross-matching procedure?

  1. Place one drop of patient’s serum in a prelabeled glass test tube.
  2. Add one drop of 5% saline suspension of donor’s red cells.
  3. Mix and incubate at 37°C for 15-30 minutes.
  4. Centrifuge at 1000 rpm for half a minute.
  5. Examine for agglutination or hemolysis.
• What does no agglutination or hemolysis indicate in major cross-matching?

  It indicates compatibility between the donor's blood and the recipient.
• What does agglutination or hemolysis indicate in major cross-matching?

  It indicates mismatching and that the recipient should not be transfused with the tested donor blood/component.
• What is the procedure for minor cross-matching?

  1. Take one drop of donor’s serum and one drop of 5% saline suspension of recipient’s red cells.
  2. Incubate at 37°C for 15-30 minutes.
  3. Centrifuge at 3000 rpm for half a minute.
  4. Observe for agglutination or hemolysis.
• Why is it necessary to monitor the recipient during and after transfusion?

  To deal with any complications that may arise.