The immunoglobulins are Ig G , Ig A , Ig M , Ig E , Ig D ( Remember GAMED ) First Immunoglobulin to appear is Ig M - i MM ediate Immunoglobulin with M aximum M olecular weight - Ig M = M illionaire molecule; Also, M aximum sedimentation coifficient is for Ig M Ig A A ctivates A lternative complement pathway Major serum immunoglobulin is Ig G - ma G or Ig G crosses placenta ( G estation )