Question

how are red blood cell suspensions prepared for ABO/D testing?

2. What reagents are used to detect ABO/D antigens?

3. What reagents are used to detect ABO antibodies?

4. How are ABO/D testing reactions read and graded?

5. How is ABO/D testing interpreted?

Answer 1

ABO/D is the test used to determine ABO incompatibility.

ABO blood group system , is determined by the presence of Antigens A , B or AB.

D antigen refers to the Rhesus factor that was discovered by Landsteiner and Wiener.Presence of D antigen refers to "Rh positive", absence of D antigen is referred to as "Rh negative".

1. Preparation of Red Blood Cells suspension for ABO/D testing:

5% of Red Blood cell suspension in ID Diluent 2.

• Allow the Diluent to reach the room temperature before use.
• Dispense 0.5 no of ID Diluent 2 ,in to a glass tube.
• Add 50 micron ml of whole blood or 25 micron ml of packed cells.
• Mix all the Diluent gently.

2. Reagents used to detect ABO/D antigens:

• Monoclonal Anti A
• Monoclonal Anti B
• Monoclonal Anti D
• ID- Diluent 2
• ID Diacell A1, and B

​​​​​​​3.Reagents used to detect ABO antibodies.

• Anti A
• Anti B
• Anti A, B

​​​​​​​4. ABO/D testing reactions and grades.

Grading can be given according to the reactions of the test.

Grades	Results	Reaction
-	Negative	No visible agglutination at the bottom of the tube
+/-	Positive	Few agglutinated RBCs are visible above the pellet of the tube
1+	Positive	Agglutinated RBCs visible in the lower half of the gel column.
2+	Positive	Agglutinated RBCs were distributed through out the entire gel column.
3+	Positive	Most agglutinated RBCs concentrated at the top of the gel

​​​​​​​5. Interpretations.

1. Anti A positive, Anti B Negative, Anti D positive

Result : ABO - A and D positive

2. Anti A positive, Anti B Negative, Anti D Negative

Result : ABO - A and D Negative

3. Anti A Negative, Anti B positive, Anti D positive

Result ABO - B and D is positive

4. Anti A Negative, Anti B Positive, Anti D Negative

Result ABO - B and D is Negative

5. Anti A, B , D are positive

Result ABO - AB and D is positive

6. Anti A, B , C Negative

Result ABO - O and D is Negative