Which of the following immunoglobulin is a pentamer?
IgM Both secretory IgA (dimeric) and IgM (pentameric) have J chains IgM is the main immunoglobulin produced early in the primary immune response. IgM is present on the surface of viually all uncommitted B cells. It is a pentamer composed of five H,L, units (each similar to one IgG unit) and one molecule of J (joining) chain.
IgG
IgA
IgM
IgD