99久久精品国产9999高清-99久久精品国产高清一区二区-99久久精品国产免费-99久久精品国产免看国产一区-99久久精品国产片-99久久精品国产片久人

Immunoglobulin M (IgM) normally constitutes about 10% of serum immunoglobulins. IgM antibody is prominent in early immune responses to most antigens and is largely confined to plasma due to it's large size. Monomeric IgM is expressed as a membrane bound antibody on the surface of B cells and as a pentamer when secreted by plasma cells. Due to it's high valency IgM is more efficient than other isotypes is binding antigens with repeating epitopes (virus particles and red blood cells) and is