An epitope associates with which part of an antigen receptor or antibody?

Answer

Variable regions of a heavy chain and light chain combined

Explanation:

An epitope refers to  or can be explained as the specific target against which an individual antibody binds. It can further be described as the part of the antigen that binds to a specific antigen receptor on the surface of a B cell.

It should be understood that, an epitope  is capable of stimulating an immune response. And, it can be used in proteomics and the study of other gene products.

Finally, on the antigen or antibody, an epitope is known to associate with variable regions of a heavy chain and light chain combined.