Final answer:
The major difference between a heterogeneous and homogenous immunoassay lies in the distribution of the components in the assay mixture.
Step-by-step explanation:
The major difference between a heterogeneous and homogenous immunoassay lies in the distribution of the components in the assay mixture.
In a heterogeneous immunoassay, the components are physically separated. This means that the target analyte and the detection reagents are not in direct contact with each other. Examples of heterogeneous immunoassays include solid-phase immunoassays, such as enzyme-linked immunosorbent assays (ELISAs), where the target analyte binds to a solid surface and is then detected using labeled antibodies.
On the other hand, in a homogenous immunoassay, the components are mixed together in solution and are in direct contact with each other. This means that the target analyte and the detection reagents are free to interact with each other. An example of a homogenous immunoassay is a fluorescence immunoassay, where the target analyte is detected based on the change in fluorescence signals upon binding to labeled antibodies.