The present invention relates to a method for stabilization of analytes in solutions of solubilized body samples. The method comprises the steps of solubilizing the body samples obtained from a subject in a suitable sample medium and stabilizing said body sample contained within the sample medium by heating said sample medium for a certain period of time. A further aspect of the invention is a method of a denaturing immunoassay of proteins in solution. The method comprises the steps of bringing a sample containing proteins into contact with a denaturing agent and heating said sample in the presence of the denaturing agent to allow the protein to be denatured.