<prompt> which antibody is called the millionaire moleculeIgAIgMIgGIgD  <response>: IgM: Immunoglobulin M IgM, the largest pentameric immunoglobulin is used as a marker of recent primary infection for some diseases. IgM constitutes 5-10 of serum immunoglobulins in adults. IgM has a half life of 5 days. Because of its high molecular weight 900,000- 1000,000, it is often called macroglobulin and the millionaire molecule Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 98 