出典:Wikipedia
出典:『Wikipedia』 (2011/05/15 17:29 UTC 版)
Immunoglobulin M, or IgM for short, is a basic antibody that is produced by B cells. It is the primary antibody against A and B antigens on red blood cells. IgM is by far the physically largest antibody in the human circulatory system. It is the first antibody to appear in response to initial exposure to antigen.