ABO Blood Grouping

ABO Blood Group

ABO Blood Grouping is a common test that we have done in our school. However, it is slightly different in the hospital.

ABO Blood Grouping is done to determine the Blood Group of a person using Antibody-Antigen reaction. It has two different parts, one Forward grouping and the other Reverse Grouping. Forward grouping is the reaction between Commercial Serum/Antibody and Patient’s Diluted Blood Antigen. Reverse Grouping is the reaction between Commercial Red Blood Antigen and Patient’s Serum/Antibody.

The tubes are then centrifuged and are checked for agglutination. If there’s agglutination, it shows that there is Ag-Ab reaction. For example, under forward grouping for α tube, only have agglutination; it means that the person has A antigens from the red blood cell. Thus there might be a possibility that the person is Blood Group A. Reverse Grouping is then used to check, thus if there is agglutination in tube B, it shows that the patient has anti-B. This can confirm that the patient is Blood group A since the patient cannot have anti-A if not it will cause transfusion reaction.

Adult ABO Blood Group Procedure

· Print out ABO Blood Group worksheet from the Laboratory Information System using the test code 420500

· Collect the EDTA blood tube and ensure the name and sample number matches with the worksheet printed before proceeding to the test

· Prepare 9 glass/plastic tubes

· Label 4 tubes α, β, αβ and anti D for forward grouping

· Label 3 tubes A, B and O for reverse grouping

· Pour about 1-2ml of Blood into a new tube

· Centrifuge the tube for 5 minutes to collect serum

· Pour about 1-2ml of saline solution into a new tube, prepare blood suspension by pipetting
blood into the saline, and ensure that the blood suspension has about the same colour as the
commercial Red Cell Antigen.

· Pipette 1 drop of Commercial Serum into tubes α, β, αβ and anti D

· Pipette 1 drop of Commercial Red Cell Antigen into tubes, A, B and O

· Pipette 1 drop of Blood Suspension into tubes α, β, αβ and anti D

· Pipette 2 drops of Serum into tubes A, B and O

· Place all 7 tubes into the centrifuge machine and centrifuge for 15 s

· Take all the tubes out and check for agglutination

· Record the Blood Group of Patient

· Ask another Medical Technologist to verify the results you recorded


Baby ABO Blood Group Procedure

Baby ABO Blood Group Procedure is about the same as the adult one. Only that, forward grouping is done only. Reverse grouping is not done, this is because baby do not produce antibodies at young age. So even serum is retrieved by centrifuging, there are no antibodies.

· Print out ABO Blood Group worksheet from the Laboratory Information System using the test code 420500C

· Collect the EDTA blood tube and ensure the name and sample number matches with the worksheet printed before proceeding to the test

· Prepare 5 glass/plastic tubes

· Label 4 tubes α, β, αβ and anti D for forward grouping

· Pour 1-2ml of blood into a new plastic/glass tube

· Wash 3 times with saline solution with each sending for centrifugation

· Each centrifugation is to be 1 minute at 1006g

· Prepare blood suspension and ensure it is of the same tone/colour as the commercial Red Cell Antigen

· Pipette 1 drop of Commercial Serum into tubes α, β, αβ and anti D

· Pipette 1 drop of Blood Suspension into tubes α, β, αβ and anti D

· Place all 4 tubes into the centrifuge machine and centrifuge for 15 s

· Take all the tubes out and check for agglutination

· Record the Blood Group of Patient

· Ask another Medical Technologist to verify the results you recorded

Take note of the blood group, if the results are either AB blood group or Rhesus negative for any blood groups. There is a need to request for baby’s own blood to determine and reconfirm its blood group. As the test is done by using Baby’s Cord Blood, which may have a possibility that the blood of the mother got mixed with Baby’s cord blood, thus giving a discrepancy in the result.

Thats all for me!

Jordan Wong Wei Jie
TG02 0703992H
Grp 09