In a compatibility test using a 10% red cell suspension in saline, what is the most likely outcome?

In a compatibility test, particularly when using a 10% red cell suspension in saline, the concentration of red cells can impact the results of the test. At higher concentrations, such as 10%, there may be more antigen present than there are antibodies available to bind to those antigens, which can lead to a situation where the immune response does not occur as expected. This scenario is referred to as an "antigen excess" condition.

In the context of blood typing or compatibility testing, when there is an excessive amount of antigen in relation to the antibody, the antibodies might not be able to bridge the gap between the cells due to saturation. This results in the inability to detect agglutination, even though there is a compatibility reaction happening at a lower concentration of cells or with another diluent.

Consequently, in this specific test setup, a false negative result can occur because the expected reaction (agglutination) does not happen due to the overwhelming presence of antigens incapable of interacting effectively with the antibodies present. Thus, this leads to an incorrect interpretation of compatibility based on the observed results.

In contrast, the prozone phenomenon typically results in false negative outcomes, but it is usually associated with certain serum antibody concentrations rather than the