<prompt> Which immunoglobulin is scarce in human serum-IgAIgGIgMIgE  <response>: IgE is an 8 S molecule. - resemble IgG structurally. - heat liable - affinity for the surface of tissue cells of the same species. - normal serum contains only traces of IgE a few nanograms per ml - greatly elevated levels in atopic conditions like asthma, hay fever. REF:Anathanarayan panikers 9th edition, pg no: 98,98 p 