Question

Agglutination refers to irregular, variably-sized clumps of RBCs that form because of

a. Excess antibodies bound to the surface of RBCs.
b. Inadequate volume of anticoagulant used.
c. Improper temperature at the time of sample collection.
d. Improper sample handling.

Answer 1

Agglutination occurs when an antibody binds to antigens on multiple red blood cells, creating clumps. This process can be caused by either antibodies produced by the body or certain viruses. The irregular clumps observed by the student are likely due to excess antibodies on the RBCs.

Step-by-step explanation:

Understanding Agglutination

Agglutination refers to the visible clumping of red blood cells (RBCs), often due to the presence of antibodies that bind to self-RBC antigens causing an immunological response. When antibodies, typically IgG or IgM, encounter antigens on the surface of RBCs, they attach via their Fab antigen-binding sites. If an antibody attaches simultaneously to antigens on multiple cells, it links the cells together, forming clumps. This is particularly important in blood typing, where the ABO blood group antigens cause specific agglutination patterns that can indicate a person's blood type. Additionally, agglutination assays can be performed to detect the presence of antibodies against pathogens or in cases of autoimmune diseases.

In the student's question, the irregular, variably-sized clumps of RBCs, known as hemagglutination, occur due to a. Excess antibodies bound to the surface of RBCs. Agglutination is used as an indicator of antibody presence against bacteria or RBCs. It is not caused by inadequate anticoagulant, improper temperature, or sample handling. However, it can also occur due to certain viruses that bind to the RBCs and cause cross-linking. While IgG antibodies bound to RBCs generally do not cause visible agglutination, the addition of Coombs' reagent can promote agglutination by linking IgG attached to neighboring red blood cells.

Answer 2

Agglutination is the clumping of red blood cells caused by the binding of antibodies to their surface. This is often used as an indicator in lab assays and can lead to physiological effects like vessel blockage and hemolysis. The correct option causing agglutination is 'Excess antibodies bound to the surface of RBCs'.

Step-by-step explanation:

Understanding Agglutination

Agglutination refers to the clustering of red blood cells (RBCs) into irregular, variably-sized clumps. This phenomenon typically occurs when antibodies bind to antigens present on the surface of erythrocytes, commonly as part of an immune response. One form of this is hemagglutination, which may occur during transfusion reactions, where antibodies attach to antigens on the surfaces of foreign erythrocytes leading to their clumping together. Such agglutination can have significant physiological effects, including the blockage of blood vessels, deprivation of tissues of oxygen and nutrients, and hemolysis (destruction of red blood cells).

In the context of laboratory assays, agglutination is used as an indicator of the presence of antibodies against bacteria or red blood cells. Notably, with antigens on RBCs, the presence of antibodies may not always lead to visible clumping because of the nature of the immunoglobulins, such as IgG. A special reagent, the Coombs' reagent, is often added to promote visible agglutination by linking IgG antibodies on neighboring RBCs.

In summary, the clumps referred to in agglutination consist of RBCs bound by antibodies. The correct answer to the question of what causes agglutination is a. Excess antibodies bound to the surface of RBCs. This cause is aligned with the role of antibodies in the immune response and their prevalence in laboratory assays.