Which of the following statements is/are true regarding IgM?
All of these
IgM is the first antibody produced in a primary response to antigens. It exists as a monomer, similar in structure to IgG when bound to the B cell surface, but its secreted form is a pentamer, in which five such monomer units are held together by disulphide bonds that link their heavy chain domains. The pentamer form makes it the largest immunoglobulin making it difficult for IgM to diffuse between intercellular spaces.