PRINCIPLE AND TECHNIQUE IN ABO
Principle
Reverse grouping indicates the presence or absences of anti-A and anti-B in serum.
Techniques & procedures
Slide technique
Tube technique
- Add two drops of serum to be tested in each tube.
- Add one drop each of A and B cells suspension to the corresponding test tubes.
- Mix well and centrifuge both tubes at 1000 rpm for 1 minute.
- Gently remove the tubes and completely resuspend cells and examine macroscopically for agglutination and if negative, microscopically.
- Record the reactions and interpret the results
- Add a drop of serum to be tested on both sides.
- Using a clean applicator stick, mix the serum and cell suspension on both sides separately and spread into a smooth round circle.
- Add a drop of serum to be tested on both sides.
- Rock the slide gently for 2 minutes and look for agglutination.
- Mark a clean slide into two halves, labeling the left and right side side as A and B.
6.Record the reactions and interpret the results.
Principle
FORWARD
principle:
The forward grouping is the presence or absence of A and B antigens in RBCs.
Techniques & procedures
slide technique
- Place a tiny drop of well-mixed blood, either capillary or venous, on each slide.
- Using an applicator stick, combine one drop of blood with the anti-A.
- Using a clean applicator, repeat the procedure with anti-B and the other drop of blood.
- The slide is gently bounced for two minutes before being examined for agglutination under adequate lighting. Agglutination is a positive response that causes red blood cells to cluster together.
- Positive (+) or negative (-) outcomes should be reported (0).
tube technique
- Add eighteen to nineteen drops of saline to one drop of the patient's blood to make a 2-5 percent red blood cell suspension.
- Set up two tubes, one labelled "A" and the other "B," with one drop of anti-a serum in the "A" tube and one drop of anti-B serum in the "B" tube.
- Add one drop of the patient's 2-5 percent cell suspension to each tube and mix thoroughly.
- To speed up the process, the tubes are centrifuged for thirty seconds. After then, the tubes are removed from the centrifuge.
The presence or absence of the A, B and D antigen on human red blood cells can be determined by testing the red blood cells with the respective antisera, specifically Anti-A, Anti-B, Anti-AB and Anti-D. It is based on the principle of agglutination.
- ABO slide grouping is done with a commercial typing slide or a clean microscope slide divided into two half with a wax pencil.
- Apply one drop of commercial anti-A serum to the left side and one drop of commercial anti-B serum to the right.
REVERSE
- Label two test tubes as A and B.
NAME& ID:
1] ABIGAIL PRIYANKA THOMAS [012020090673]
2] ROSHINI A/P R ASOGAN [012020091620]