久久国产精久久精产国,亚洲 国产 另类 无码 日韩,扒开腿狂躁女人视频免费,精品人妻无码一区二区三区绿

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