Two methods of determining ABO and Rh groups Essay

Two methods of determining ABO and Rh groups - Essay Example The paper tells that because of Rh and ABO, it is important to be able to chemically identify the different blood types. In the ABO blood group system there are two types of marker that are present on the blood cells. These are type A and type B. If an individual has neither of these markers then they are considered to be type O. Individuals can be of blood type A, B, O or AB, as they inherit one type of marker from each parent. The human body does not produce antibodies for the markers that it contains, but does so for the ones that are not present. This is because the immune system sees the foreign marker as an invader and consequently defends itself against it. Thus, a person with type AB blood does not have antibodies against either A or B markers, and can consequently receive blood from any blood type. However, they also cannot give to any other blood type. In contrast, someone with type O blood can donate blood to any blood type as no antibodies will be raised, and but can rece ive blood only from other type O donors. Another factor that is present in the blood of humans is known as the Rh or rhesus system. This was first discovered through immunization of rabbits with blood that had been obtained from rhesus monkeys. It was found that the antibodies in the rabbit caused the blood to cogulate. Although the Rh system contains around 50 different antigens, five of which are considered to be the most important (D, C, c, E and e), and of these the D antigen is the most relevant. It is often thought to be the most polymorphic blood group system in humans. ... Secondly, the study used antibody screening on two plasma samples to determine the presence of antibodies. Materials and Methods Tube Grouping: Rh (D) and ABO antigens in unknown samples Four agglutinin reagents were to used in this experiment, Anti-A, Anti-B, Anti-A,B and Anti-D Alpha. These reagents react directly with the antigens present in red blood by making the cells clump together. Thus, they could be used to determine the blood type of each of the four patients. Sixteen clean test tubes were taken and labelled with patient name (Patient 1, 2, 3 or 4) and one of the four reagents so that for each patient there was a total of four tubes, each labelled with the name of a different reagent. Two drops of the labelled reagent were added to each tube. For each of the four patients, the cell sample was inverted several times to ensure the cells were thoroughly mixed, and then one drop of cells was placed in each of four test tubes for that patient. The cells were incubated at room t emperature for 15 minutes and then examined for agglutination. Ortho ABD and Reverse Cassettes: Rh (D) and ABO antigens in unknown samples For this section of the experiment, the same four patient samples were used. The samples were inverted to mix them and then they were loaded into the cassettes. One cassette was used for each patient and these were labelled. Each cassette had four marked wells, A, B, D and control. In each well 10 Â µl of the respective patient sample was placed. The cassettes were then placed in the Ortho Centrifuge and spun for five minutes, and then the results read. Antibody Screening An Ortho Poly AHG cassette was provided. This had six wells that contained Poly Specific Anti – Human Globulin. Three antibody-screening cells