Blood grouping

BLOOD GROUPING (A B O) Aim: to determine the blood group status of patients. Materials: whole blood sample, tile, grouping reagent, a Pasteur pipette, stirrer and cotton wool. Procedure: the patient’s blood sample is collected and dropped on three spots of a grease free tile by a dropper, anti-A, Anti-B, and Anti-D reagents are added to the first, second and the third spots of the tile respectively, it is mixed and rocked for 5 minutes. Principle: this result in an agglutination reaction between an antigen and antibodies (funk; tabatabai;hargiusi;martin and Hoffman; 2005).Human blood types are determined by the presence or absence of 2 types of antigenic glycoprotein in the membrane of RBCsABO blood group antigens: A antigen B antigen D antigen The presence or absence of Rhesus antigen determines the rhesus factor of an individual. Someone with the Rhesus antigen on the RBCs has a positive rhesus factor while someone without the Rhesus antigen on the RBCs has a negative rhesus factor. Problems with blood transfusions arise because plasma normally contains antibodies to the ABO antigens People make antibodies to the RBC antigens that they do NOT possess in their body thereby causing complications in their body system after blood transfusion. •Type A has anti-B antibodies •Type B has anti-A antibodies •Type AB has no antibodies in the plasma •Type O has both anti-A and anti-B antibodies •Rhesus positive blood has anti-Rhesus antibodies in their plasma •Rhesus negative blood has no anti-Rhesus antibodies in their plasma So therefore ABO Blood group test is usually carried out in order to know the type of antigen and Rhesus factor that the hemoglobin of an individual has on its Red blood cell. Antigen Results A B D (Rhesus factor) + + + AB Rhesus D Positive + + _ AB Rhesus D negative + _ + A Rhesus D Positive + _ _ A Rhesus D Negative _ + + B Rhesus D Positive _ + _ B Rhesus D Negative _ _ + O Rhesus D Positive _ _ _ O Rhesus D Negative Table 4: shows the result format of ABO rhesus blood grouping N/B += Agglutination _= No Agglutination Results: agglutination in the first and third spots indicated A rhesus D positive. Agglutination in the second and the third spots indicates B rhesus D positive. Agglutination only in the third spot indicates O rhesus D negative