Du Test By Tube Method
Title: Du Test by Tube Method
Aim: To perform the Du test by tube method
The D antigen is the most immunogenic antigen in the Rhesus blood group system. Rhesus positivity and negativity indicate the presence or absence of the D antigen on the surface of red blood cell. Du test is the further testing that is done to identify Weak D antigen when the cells being tested have failed to react with anti-D antisera at immediate spin. An indirect antiglobulin test is essential to identify patients with the Weak D antigen. The red blood cells are incubated at 37˚C with anti-D and then tested with anti-human globulin (AHG) reagent. This test is done on prenatal patients and candidates for Rhesus immune globulin. Du is also done on Rhesus negative patients to ensure they are truly Rhesus negative. It may or may not be done routinely on Rh negative candidates for transfusion, depending on the policy of the transfusing institution. If …show more content…
Test tube, Pasteur pipette, centrifuge, microscope, glass slide, normal saline, Anti-Human Globulin (AHG), Coomb’s Control Cells (CCC) and Anti-D.
1. 5 % cell suspension of the patient’s red cell in saline is prepared.
2. 2 drops of Anti-D is added to a test tube marked as ‘Test’
3. Two drop of patient cell suspension is added to the tube marked as ‘Test’.
4. Tube is mixed and immediate spinned at 3000 rpm for 15 seconds.
5. The agglutination is checked. Presence of agglutination is considered as positive Du test.
6. Incubated at 37oC for 30 minutes if agglutination is absent.
7. Centrifuged at 3000rpm for 15 seconds and checked for agglutination. Presence of agglutination is considered as positive Du test.
8. The cells are washed 3 times with normal saline if absence of agglutination.
9. Two drops of Anti-Human Globulin (AHG) is added to the sedimented